MIL-HDBK-705C29Flay1987SUPERSEDINGMIL-HDBK-705B26June1972MILITARYHANDBOOKGENERATORSETS,ELECTRICAL,MSASUH)WSNTANDINSTRUIIENTATIONMSTHODSFSC6115AMSCN/ADISTRIBUTIONSTATEMENTA.
Approvedforpublicrelease;distributionisunlimitedDownloaded from
http://www.everyspec.com-:.., ~..;.,,,..;.. . ... ...
.DEPARTMENTOFDEFENSEWASHINGTON, D
.C.20301MIL-HDBK-705CGeneratorSets,Electrical,MeasurementandInstrumentationMethods1.
ThisMilitaryHandbookwaad&veloDedbv theUSArmyTrOOD
SuuportCommand-BelvoirRe~earchDevelopmentandEng~aeeringCen~erinacc~~dance
withMIL-STD-962andisapprovedfortheuseofallDepartmentsU.S.Government.2.
Thispublication,revisionC,was.approvedon29printingandinclusioninthemilitaryhandbookseries.andAgenciesof
theHay 1987,for3. Thiedocumentprovidesbasicandfundamental
information
onmeasurementandinstrumentationmethodsforevaluationofelectricalpowergenerators,generatorsetsandrelateditemewhen
theseitemsaretestedinaccordance
withMIL-sTD-705andsimilartestmethods.4.
Beneficialcomments(recommendations,
additions,deletions)andanypertinentdatawhichmaybeofuse in
improvingthisdocumentshouldbeaddressedto:
USArmyTroopSupportCommand- BelvoirResearchDevelopmentandEngineering
Center,ATTN: STRBE-DS,FortBelvoir,VA 22060-5606,
byusingtheself-addressed Standardization DocumentImprovement
Proposal(DDForm1426)aPPearlngat theendof thisdocument,orby
letter.iiDownloaded from
http://www.everyspec.comMIL-HDBK-705CFOREWORD1. Thishandbook is
intendedtoexplainandestablishconventionsforterminology,instrumentation,
methodsofmeasurementandacceptedproceduresassociatedwith
thetestingandevaluationofelectricgenerators,generatorsets,andrelateditems.
Itistobe usedinconjunction
withMIL-STD-705todeterminecapabilities,conditionsandcompliancewith
therequirementsofprocurementdocuments.
Themethodshereincontainpreparatoryproceduresandbasicdetailedrequirementsforgeneraluse
instruments, measurementsandinstrumentation,whilethemany
specificmethodsof
testareestablishedinMIL-sTD-705,GeneratorSets,Engine-Driven,TestMethods
andInstructions.2. Sometestinstrumentsillustrated hereinareno
longerbeingmanufacturedandtheirfunctionshave beensupersededby
newertypesof instruments;theoldertypes,however,arestillbeing
usedinsomeareasandarestillacceptable;therefore,theirinclusioninthishandbookwillbecontinueduntilsuchtimeastheirremovalwillbe
in theGovernmentsbestinterest.3.
BecausethishandbookiscloselyalliedtoMIL-STD-705,referencesfromonetotheotherarefreelyusedparticularlyfromMIL-STD-705tothisdocument.Inspectorsandtesterswill
findneed forboththehandbookandstandardwhenworkingwith
electricalpowergenerationequipment.4. Dueto thecomplexityof
specifiedrequirementsinprocurement
documentscoveringengine-drivenelectricgeneratorsandothersimilartypeaofelectricmachinery,militarypersonnelwill
findthishandbookespeciallyhelpfulasaconvenientsourceofgeneralinformationonelectricalinstruments
andtheirproperuse. Thie
technologyhasbeendocumentedfromexperiencebygovernmentandindustryengineersand
technicianswiththemanufacturing,procurementandtestingofelectricalpowergenerationequipment..
..111Downloaded from http://www.everyspec.comMIL-HDBK-705CPAM
.1.1.11.21.2.11.2.22.3.4.5.5.1MethodCONTENTSREVISIONSTATUSOFMETHODS
.......................................LISTOFFIGURES(NUMERICORDER)..................................CROSSINDEX-
SUBJECTS-TO-FIGURES................................SCOPE.............................................................COVERAGE..........................................................NUMBERINGSYSTEM................................................METHODNUMBERS....................................................DECIMALSYSTEM...................................................REFE8RNCED
DOCUlf3NTS.............................................DEFINITIONS......................................................GENE8ALREQUIREMENTS.............................................DETAILEDREQUIREMENTS............................................INSTRUMENTSANDMRASURRMENTS-
100SERIES........................No. Method101.1-
MeasurementofPotential.....................................102.1-
Measurementoccurrent .......................................103.1-
MeasurementofPower .........................................104.1-
MeasurementofFrequency.....................................105.1-
MeasurementofRe,si6tance....................................106.1-
MeasurementsofTransientsandWaveforms .....................107.1-
MeasurementofPowerFactor..................................108.1-
MeasurementofTime ...........................................109.1-
MeasurementofSpeed.........................................110.1-
MeasurementofTemperature...................................111.1-
MeasurementofWeightandForce ..............................112.1-
MeasurementofPressure......................................114.1-
Temperature Control (Hot Rooms)..............................114.2-
TemperatureControl(Cold Rooms).............................114.3-
TemperatureControl(Altitude Chambers)......................115.1-
MeasurementofSoundLevel ...................................116.1-.
.Determmatlonof PhaseRotation..............................117.1-
DeterminationofPhaseRelationship..........................5.2
INSTRDlfiNTATION
METHODS-200SERIES.............................MethodNo.
Method201.1- ElectricalInstruments:CareInspection, Use,
andRequiredAccuracy
...........................................202.1-
ThermalInstrumentation......................................PAGEviviixi11111248:923323540505965697481828587909294979899102ivDownloaded
from http://www.everyspec.com.. . . .. .MIL-HDBK-705C203.1-
DataSheetsandRecordEntries ...............................205.1-
GeneralInstructionsforConnectingTestingInstruments......220.1-
EnginePressureMeasurements.................................220.2-
PressureandTemperatureCorrectionstoSparkandCompressionIgnitionEngineData
...........................221.1- Temperature
CorrectionstoResistanceMeasurements...........222.1-
BatteryServicingandConditioningPriortoColdStartingTests
............................................6. NOTKSAND
CONCLUDINGMATERIAL....................................APPENDIX
A-LOADBANKS
................................................108110165166170171177178Downloaded
from http://www.everyspec.com::.-
:MIL-HDBK-705CREV1S1ONSTATUSOFMETHODSMethodNo. Revision
Date101.1102.1103.1104.1105.1106.1107.1108.1109.1110.1111.1112.1114.1114.2114.3115.1116.1117.1201.1202.1203.1205.1220.1220.2221.1222.1-----
-b----- -b----- -b----- -b----- -b----- -b---- --b----- -b-----
-b----- -b----- -b----- -b----- -b---- --a---- --a---- --a-----
-b---- --b---- --b---- --b---- --b---- --b----- -b----- -b-----
-a----- -aReplacedby(ifMethoddeleted)viDownloaded from
http://www.everyspec.com~~MIL-HDBK-705CFIGUP.SS101.1-1101.1-2101.1-3101.1-3.1101.1-3.2101.1-4101.1-4.1101.1-5102.1-1102.1-2102.1-3102.1-3.1102.1-4103.1-1103.1-1.1104.1-1104.1-2104.1-3104.1-3.1105.1-1105.1-2105.1-3105.1-4105.1-5106.1-1106.1-2106.1-2.1106.1-3106.1-4107.1-1107.1-1.1107.1-2108.1-1108.1-2RepresentativetypesofdcVoltmeters
..................Seriesresistancemultiplier
...........................RepresentativetypesofacVoltmeters
..................Representativetypesof acVoltmeters
..................Representativetypesof acvoltmeters
..................Acceptabletypeof recordingvoltmeter
.................Acceptabletypeofrecordingvoltmeter
.................Potentialtransformer..................................Acceptabletypeof
self-containeddc ammeter ...........dc eumeterwithrotaryshunt
...........................Representativeacaimneters.............................Representativeac
ammeters .............................ac ammeterused
inconjunctionwith
currenttransformer............................................Acceptabletypesofwattmeters
.........................Representativetypesofwattmeters
.....................Representativemeters formeasurementof
frequency.....Representative meters formeasurementof
frequency.....Acceptabletypeofrecordingfrequencymeter...........Acceptabletypeof
recordingfrequencymeter...........Kelvinbridgefo,rmeasuring
lowresistance
.............Drop-inpotentialtestconnections.....................Comparisonmethod
teatconnections.....................Wheatstonebridge
formeasuringresistances ............Acceptabletypesofmegohmmeters
......................Typicaloscilloscope...................................Typiceloscillograph...................................Typicaloscillograph...................................Typicalharmonicanalyzer..............................Transientwaveformrecorder............................Power
factormetere ....................................Power factor
meters ...............................!....Phaseanglemeter
......................................Sampleoscillogramshowingmedianline.................Typicaloscillograph...................................9101112131415161920212223252629303132383940414247484950515556576061viiDownloaded
from
http://www.everyspec.com109.1-1109,1-1.1109.1-2110.1-1110.1-2112.1-1114.1-1114.2-1115.1-1116.1-1116.1-2201.1-1202.1-1202.1-2202.1-3205.1-1205.1-2205.1-3205.1-4205.1-5205.1-6205.1-7205.1-8205.1-9205.1-10205.1-11205.1-12205.1-13205.1-14205.1-15-,
>.-..MIL-HDBK-705CFIGURES(corit
inued)PAGERepresentativetypeofspeedandrevolutioncOunter...Representativetype
ofspeedandrevolution counter...Representative
hand-typetachometers..................Varioustypesof
thermocouples........................Multiple-sensorautomaticdata-loggingsystem.........Representative
typesofmanometers ....................Layoutfortypicalhotroom
..........................Scheinat
icdiagramofcontrolledlowtemperaturechamber..................................................7172737980848689Soundlevelmeter
....................................Portablephaserotationindicators....................Makeshiftphaserotationindicator....................(Figuredeleted,blankpagemaintained)...............Immersedandexposedthermometers.....................Thermometerplacementformeasuringambientairtemperature
whiletestingtwogeneratorsets..........Thermometersor thermocouples
locationsformeasuringtemperature
ofelectrolytein6-,12-and24-voltbatteries......................................Self-contained
acvoltmeter
..........................acvoltmeterwithpotentialtransformer...............,.acvoltmeterwlth
multiplier..........................Schematicdiagramofvoltmeterwithselectorswitchforlme-to-lme
voltagemeasurements..........Potentialselectorswitch.............................Recordinginstrument
withelectricdrive..............Self-contained
dcvoltmeter...........................Self-contained
acammeterwithprotectiveswitch......acammeterwithcurrenttransformer
usingtaps........ac
ammeterwithcurrenttransfOrmeruaingwrappedturns.........................................AUMIet
er
tranaferswitch...............................acammeterwithcurrenttransformers
andselectorswitch................................................Self-contained
dcarmneter.............................dcammeterwithahunt.................................Single-phaae
wattmeter................................939596101105106107118119120121122123124125126127128129130131132.
. .ViiiDownloaded from
http://www.everyspec.comMIL-HDBK-705CFIGUSES(continued)205.1-16205.1-17205.1-18205.1-19205.1-20205.1-21205.1-22205,1-23205.1-24205.1-25205.1-26205.1-27205.1-28205.1-29205.1-30205.1-31205.1-32205.1-33205.1-34205.1-35205.1-36205.1-37205.1-38Single-phasewattmeterwithpotentialtransformer......Single-,
phasewattmeterwithcurrenttransformer........Single-phasewattmeterwithpotentialandcurrenttransformer............................................Single-phasewattmeterwithwyeboxon
three-phase,three-wue
balancedsystem.............................Single-phasewattmeteron
three-phase,three-wirebalancedsystemusing
twocurrenttransformers.........TWO single-phasewattmeterson
three-phaae,three-wiresystem......................................Two-element,polyphaaewattmeteron
three-phase,three-wiresystem
......................................Two-element,polyphasewattmeteronbalancedthree-phase,four-wiresystem
.......................................Twoelement,polyphasewattmeterwithpotentialtransformersonbalancedthree-phase,four-wiresystem.TWOelement,polyphasewattmeterwith
currenttransformersonbalancedthree-phase,four-wiresystem.Twoelement,polyphasewattmeterwithbothcurrentandpotentialtransformersonbalancedthree-phase,
four-wxresystem
............................................Threewattmetersusedonunbalancedthree-phase,four-wiresystem
............................................Polyphasewattmeterusedon
single-phasesystem........Polyphasewattmeterwithcurrentandpotentialtransformersusedasasinglephaseinstrument.........Single-phasepower
factormeter
........................Single-phasepowerfactormeterwithcurrentandpotentialtransformers.................................Three-phasepower
factormeter .........................Three-phasepower factor
meterwithpotentialtransformers...........................................Three-phasepower
factormeterwithcurrenttransformer.Three-phasepower
factormeterswithcurrentandpotentialtransformers.................................Single-element
wattmeterusedasavarmeteron
three-phasebalancedcireuit.................................PolyphaBevarmeter
circuit.............................Frequencymeter
........................................PAGE13313413513613713?139.,.14U141142143144145146147148149150151152153154155ixDownloaded
from http://www.everyspec.com-
MIL-HDBK-705C205.1-39205.1-40205.1-41205.1-42205.1-43205.1-44205.1-45205.1-46205.1-47220.2-1FIGURZS(continued)PAGEFrequencymeterwithpotentialtransformer.............
156Recordingfrequency meter............................... 157Load
instrumentationfortwo-wirydcgeneratorset ..... 158Load
instrumentationforthree-wire dcgeneratorset...
159Loadinstrumentationforsingle-phase,
two-wireacgeneratoraet..........................................
160Load inatrumentationforsingle-phaae,
three-wireacgeneratorset.......................................
161Loadinstrumentationforthree-phase, three-wireacgener~toraet
....................................... 162Load instrumentation
forthree-phase,four-wireacgeneratoraet
.......................................... 163Load
instrumentationforshortcircuitcurrents........
164SlingPsychrometer.....................................
169xDownloaded from http://www.everyspec.com.\,
--tfIL-HDBK-705cCROSS-INDEX:
SUBJECT-.TO-FIGURESSUBJECTORKEYWORDSAmmeter,acAmmeter,ac,Ammeter,dcAmmeter,dc,Ammeter,dc,Ammeter,dc,.
. . . . . . . . . .. . . . . . . .. . . .. . . . . . .. .. .. ..
.used/wcurrenttransformer
.,..............................................self-contained
......................withrotaryshunt ...................with shunt
..........................Analyzer,harmonic
...............................Automaticdata-loggingsystem,multiplesensor
...Bridge,kelvin
...................................Bridge,Whetstone
...............................Connections,test,comparisonmethod
.............Connections,test,drop-inpotential
.............Counter,revolutionand speed
....................Counter,speedandrevolution
....................CurrentCurrentmeterCurrenttransformer,usewithac
ammeter .........transformer,usewith power
factor..........................................transformer,usedwithwattmeter
.........Data-loggingsystemautomatic,multiple sensor
...Frequencymeter ..................................Generatorset,
ac, single-phase,two-wire,loadinstrumentation
................................Generatorset,ac,single-phase,three-wire,loadinstrumentation
................................Generatoraet,ac,
three-phase,three-wire,loadinetrumentation
................................xiPAGESFIGURBSARSON21,22,23,114,116,1182319,20,
119,12019,1192020,12050733841403964-6664-6623135,137,140123,124,130,133,1357329,144,145,146149150151Downloaded
from http://www.everyspec.com- MIL-HDBK-705CCROSS-INDEX:
SUBJECT-TO-FIGURES (continued)PAGESFIGURES
SUBJECTORKEYWORDSARRONGeneratorset,ac,three-phase,four-wire,~........................two-wire,load........................three-wire,loadDad.......
163instrumentationGeneratorset,dc,instrumentationGeneratorset,dc,instrumentationHarmonicanalyzer158
... .. . .159578616995,96. . . . ... . . . . ... . . . . .. . . ..
. ... ... .. . . . ... . .. . ... . . .. . . . . .. . ... ...
.Hotroomtypi~allayoutfor
.......................Humiditymeasuringinetrument
....................Indicator,phaserotation
........................Kelvinbridge
....................................Line-to-line
voltagemeasurements, voltmeterschematic diagramfor
..........................45121Loadinstrumentation
.............................158,164Load
instrumentation,acgeneratorset........... 160-163Load
instrumentation, dcgeneratorset...........
158,159Lowtemperaturechamber,controlledschematicdiagramfor
....................................Manometer . . . . . . . . . . .
. . . . . . . . . . . . . . .. . . . . . . . . . . . . .
.Medianline,shownonoacillogram................898487496462,63Megohmmeter
....................................Meter,phaseangle
...............................Meter,powerfactor
..............................Meter,soundlevel
.................................93Multiplier,usewithacvoltmeter
................Multiplesensorautomaticdata-loggingsystem
....Multiplier,seriesresistance
....................1208014276755,56,6854Multiplier,usewithdcammeter
..................Oscillagram
......................................Oscillograph
.....................................Oscilloscope
.....................................649695Phaseanglemeter
................................Phaaerotatinnindicator,
makeshift..............Phaserotationindicator,
portable...............xiiDownloaded from
http://www.everyspec.comMIL-HDBK-705CCROSS-INDEX:
SUBJECT-TO-FIGURES (continued)SUBJECTORKEYWORDS
PAGESFIGURESAREONPotentialtransformerusedwith frequencymeter
..........................................
156Potentialtransformer,usewithacvoltmeter .....
119Potentialtransformer,usewithpowerfactormeter
..........................................
146>148,150Potentialtransformer,usedwithwattmeter .......
133,135,141,143,146Power factormeter
............................... 147-152Power factormeter
............................... 62,63Power factormeter, three-phase
.................. 147,148Power factormeter,
three-phase.................. 149-152Power factormeterwith
currentandpotentialtransformers
...................................148,152Pres8uremeasuring
instrument .................... 84Psychrometer
.....................................169Recorder,transientwaveform
.....................58Recordingdata-loggingsystem,automatic.........
80Recordingfrequencymeter ........................
38,39,157Revolutionand speedcounter .....................
71-73Schematicdiagram,controlledlowtemperaturechamber
........................................89Schematicdiagram,voltmeterwfselectorswitch
...121Selectorswitch,usedwithvoltmeterforline-to-linevoltagemeasurements..............121Shortcircuitcurrents,loadinstrumentationfor
............................................164Shunt,usewith dc
ammeter.......................27,131Single-phasesystem,wattmeteruse...............145Slingpsychrometer
...............................169Soundleve1meter
................................93Speedendrevolutioncounter.....................71-73Tachometer,hand-type
............................73xiiiDownloaded from
http://www.everyspec.comMIL-HDBK-705CCROSS-INDEX:
SUBJECT-TO-FIGURES
(centinued)SUBJECTORKEYWORDSPAGESFIGURESARIONTemperaturechamber,low,controlled,schematic
diagramfor..........................89Temperature
measurement,ambientair,dua1generatorsettesting..........................106)Testconnections,
comparison method ..............47Testconnections, drop-inpotential
..............46Thermocouple
.....................................79Thermocouplelocationformeasuring.batteryelectrolyte
temperature
........................107Thermometerplacementformeasuringambientairtemperature
................................106Thermometer, exposed
.............................105Thermometer, immersed
............................105Three-phasesystem,varmeteruse
................. 152Three-phasesystem,wattmeteruse
................
136-144,153Three-phase,three-wireayatem,wattmeteruse ....
136,137,138Three-phase,four-wiresystem,wattmeteruae .....
140-144Transformer, potential ...........................
22Unbalancedthree-phase,four-wiresystem,wattmeteruse
.................................. 144Varmeter
......................................... 153,154Varmetercircuit
................................ 154Varmeter,polyphase
.............................. 154Voltmeter with selectorswitch
................... 121Voltmeter, ac
....................................
15-17,118,119,120Voltmeter,ac,withmulitplier ...................
120Voltmeter,ac,wlpotentialtransformer
............Voltmeter,ac,self-contained
....................Voltmeter,dc
....................................Voltmeter,electrostatic, 30-Kv
..................Voltmeter, recording
.............................Voltmeter, vacuum tubetype
......................Wattmeter
........................................11911812,1241920,211833,34,
132-146xivDownloaded from
http://www.everyspec.comSUBJECTORWattmeter,Wattmeter,MIL-HDBK-705CCROSS-INDEX:
SUBJECT-TO-FIGURSSKEYWORDSpolyphase
.............................polyphaseusedas single-phaseinstrument
.....................................Wattmeter,polyphase,with
currentandpotentialtransformers
...................................Wattmeter,eingle-element
........................Wattmeter,single-phase
..........................Wattmeter,single-phase,useof twoon
three-phase,three-wiresystem
..............................Waveformrecorder
................................Whetstone bridge
................................Wyebox,usedwithwattmeter
.....................(continued)PAGESFIGURESAREON139-143,145,146146146153132-1381385848136xvDownloaded
from http://www.everyspec.comMIL-HDBK-705C1. SCOPE1.1 Covera&.
Thishandbook coverstwoseriesofmethods formeasuringanddetermining
characteristicsofallelectricgeneratorsandgeneratorsetsaaclassifiedbyMIL-STD-1332,andassociatedequipment.
.The illustration anddescriptionof thetest instrumentstogetherwith
instructionfortheiruaeareincludedasapplicableunder eachmethod. As
noted intheforewordnfthishandbook,someof theolder typesof
instruments areno longermanufactured.1.2 Numb~ringsystemsused
inthishandbook. Textherein isidentifiedinaccordancewith
MIL-STD-962andthesampleformatsshowntherein. Methodandmethod
figurenumbering isadditionallysignificantas follows:1,2,1
Methodsnumberedin the100series.
Thesemethodspertaintobasicinstrumentaandmeasurements.1.2.2
Methodsnumbered inthe200seqiea.
Thesemethodspertaintobaaicinstrumentationproceduresandapplications.1.2.3
Revisionstomethods- identification. Lower case
alphabeticcharactersare
suffixedtothemethodnumberstoidentifyrevisionstomethods.1.2.4
Figurenumberingwithinmethods.
Thebeginningdigitsofanyfigurenumberarethesameas
themethodnumberthatfigurepertainsto.
Ahyphenisusedtoseparatethefirstand
secondportionsofthefigurenumbers.
Thedigitsusedinthesecondportionsof
figurenumberseatabliahtheorderoffigures withineachmethod;where
groupsofalternateormulti-pagefigureaoccur,suchaawhen
depictingseveraltypesormanufacturer 1modeleofinstruments used
fortbesamepurpose,thesecondportionofthe figurenumberissuffixed with
adecimaloneachof thesecondandsubsequentfiguresinvolved. The
decimalsestablishtheorderoftheaubaequentfigures
withinthat~OUp.Certainof the
figuresdepictmulti-purposeinstruments;thereforethereareseveralinstanceswhere
thepictorialcontentoffiguresisidentical,andisusedtwiceormore,but
tbefigurenumbersand
titlesdiffer,dependinguponthecategoryormethodwhere
thefigureoccurs.1Downloaded from
http://www.everyspec.comMIL-HDBK-705C2. REFERENCEDDOCUMENTS2.1
Is.sueiof.. .d.ocurnents. Thefollowingspecifications andstandards
oftheissueineffectondateof
invitationforbids,orrequestforproposal,unlessadifferentissueisspecifiedintheprocurementdocuments,formapartofthishandbooktotheextentspecified
herein.STANDARDSMILITARYMIL-STD-705MIL-STD-1332MIL-STD-1474GeneratorSets,EngineDrivenTestMethodsandInstructions.DefinitionsofTactical,Prime,Precise,andUtilityTernrinoloziesforClassificationof
theDODMobileElectricPowerGeneratorSetFamily.NoiseLimits
forArmyMateriel.(Copiesofspecifications andstandardsrequiredby
contractorsinconnectionwithspecificprocurementfunctionsshouldbeobtainedfromEnginetheprocuringactivityorasdirectedby
thecontracting officer. Copiesforotherpurposesmaybe
obtainedfromNavalPublicationsandFormsCenter,5801TaborAvenue,Philadelphia,PA
19120.)2.2 Otherpublications. Thefollowingpublications of
theissueineffeetondateof
invitationforbidsorrequestforproposal,uqleasadifferentissueisspecifiedintheprocurementdocuments,formapartofthishandbooktotheextentspecifiedherein.AMERICANNATIONALSTANDARDSINSTITUTEANSIC2-NationalElectricalSafetyCode..ANSI
C50.10thru
C50.41Series-RotatingElectricalMachinery.ANSI/ASHRAE41.6-Standard
Method forMeasurementofMoistAirProperties.ANSI/IEEE100- Standard
DictionaryofElectricalandElectronics
Terms.ANSI/NEMAMG1-MotorsandGenerators.ANSI/NEMAMG2
-SafetyStandardforConstructionandGuideforSelection,Installation
andUseofElectricMotorsandGenerators.ANSI/NFPA70-NationalElectricalCode.(includedas
generalreferences)(Copiesmaybe
obtainedfromtheAmericanNationalStandardsInstitute,
1430Broadway,NewYork,NY 10018.
Microformorcopiesarealsomaintainedatmanylibraries.)Downloaded from
http://www.everyspec.comMIL-HDBK-705CAhXRICANSOCIETYOFHEATING,REFRIGERATINGANDAIR
CONDITIONINGENGINEERS (ASHRAE).ASHRAE Handbook
1981Fundamentals,Chapter6,Psychometric
Tables.AS.HRAEBrochureonPsychrometr~.(Copiesmay
beobtainedfromASHRAE,GA 30329. Microform
orcopiesarealsoChapter5,Psychometrics,
andInc.,1791TullieCircleNE,Atlanta,maintainedatmany libraries.)2.3
Textbooks. The followingtextbooksare listedforinformation
purposesandarenot tobe
consideredasapartofthishandbook:ElectricalEngineers.Handbook,PenderandDelMar,Vol.
1,4thEd.,Wiley
Brothers,IEEEStandardDictionaryofElectricalandElectronicsTerms,IEEE100Wilby
-
Interscience.Standard,HandbookforElectricalEngineers,FinkandBeaty,llthEd.,McGraw-Hil1BookCo,ChambersDictionaryof
ScienceandTechnology(1978),HippocreneBooks.(Copies may be
obtainedfrombookstores,or
fromtbepublisherslisted;copiesarealsomaintainedatmany
libraries.)Downloaded from http://www.everyspec.comMIL-HDBK-705C3.
DEFINITIONS3.1
Extentandsourcesofdefinitions.ConsulttheANSI/IEEE100Standard,andotherreferencedocumentsofsection2herein.Downloaded
from http://www.everyspec.comMIL-HDBK-705c,-...4.
GENERALREQUIREMENTS4.1
Physicalstandards,conventionsandcali.bratio.n traceability.
Primaryandsecondarystandards,conventions,andvalues
forcalculations,computation,conversions,andcalibrationof
instruments,shallbe thoserecognizedhy
theInternationalElectrotechnicalCommission(IEC),International
OrganizationforStandardization(1S0)and
theUnitedStatesNationalBureauofStandards(NBS).TheIECand 1S0areboth
locatedinGeneva,Switzerland. IntheU.S.A.,informationregardingall
thesestandardsandconventionsmaybe obtainedfromNBS,Washington
D.C.,20234.4.2 RecycledJvirginandreclaimed.materials. Reclaimed,
recycled andrecoveredmaterials
shallbeused,whereappropriate,tothemaximumextentpossible.
Thishandbookdoesnot containanyrequirementsthatitemsbemanufactured
fromvirginmaterials, solongas theintendeduseofany
itemisnotjeopardizedthereby.5. DETAILEDREQUIREMENTS5.1
Instrum.entsandMeasurements- 100Series.5Downloaded from
http://www.everyspec.com101.1.1potential101.1.2.:.: NIL-HDBK-705C.~
NETHOD101.lb.....MSASURENENTOFPOTENTIALGE.NERAL.
Theterms,voltage~electromotive force,andareconsideredsynonymous
[email protected] DCVOLTAGE. Twotypesof
instruments arerecommendedformeasuringdcvoltage-DAr60nval
voltmetersanddigitalelectronic voltmeters(figure101.l-l).
Digitalelectronictypesshouldnotbeusedtomeasuredcvoltagewhichalsocontainsan
accomponentofanysignificance
becauaesuchanaccomponentcanpreventthesetypesfromobtainingasteadyreading.
BothDArsonvalanddigitalvoltmetersareavailableashigh-resistance
Volt-metershavingfull-scale
readingsatvaluesinthemicrovolt,andarealsoavailableas
full-eiale,self-contained
unitarangingashighas750volts.Voltmeterrangescanbe
furtherextended,evenbeyond50,000volts,byconjunctive
usewithexternally-attachedmultiplyingdevices(figure101.1-2).Suchdevices,commonlyreferred-toasseriesresistance
multipliersandseries multipliers,areprecision-made,
wire-woundresisters. Theyarecarefully manufacturedand
calibratedtobeelectricallystablewithinspecifictolerances
overrangesof temperature
andperiodsoftime.Voltmeters,especiallymillivoltmeters,shouldnotbe
connectedintocircuits
havingvoltageshigherthantheratingoftheinstrument. Tomeasurevoltages
higher thantheratingofarelativelylowresistanceinstrument, a0e7iea
resistancemultipliertlmustbeusedwith it(figure101.1-2).
Inthiscase,tbecorrectvoltageisobtainedby solving the
followingequation:E. Vr(Rv+Rm)Rvwhere:E isthevoltagetobemeasured.V=
istbereadingofthevoltmeter.Method101.lbDownloaded from
http://www.everyspec.comRv istheresistanceof thedialoron
thevoltmeterRm is theresistanceof theMIL-HDBK-705Cvoltmeter. (This
maybe foundonthevoltmetercover.)seriesmultiplier. (This value
isusuallystatedon the exteriorof theseriesmultiplierhousing.)
Thisformula,solvedforRm,canbe used
forselectingaseriesmultipliertobeusediftheapproximatevalue ofE
isknown.Becauseof
thehigh-inductive-voltagesurgewhichmaybendthepointeronDarsonvalanalogtypemeters,
dcvoltmetersshouldbe disconnectedfroma fieldcircuitbefore
thefieldswitchisopened.Becauseofhighalternating voltagesdevelopedby
transformeractioninthefieldwindingsduringstarting,dcvoltmetersalsoshouldbe
disconnectedfromsynchronous
motorsorsynchronouscondenserfieldsbeforethemachinesarestartedfromtheac
line.101.1.2.2 ACVOLTAGE. TWO typeof (RMS)sensingandindicating
voltmetersareused tomeasureacvoltage.
hesetypearedynamometer(figure101.1-3)anddigital(figure101.1-3.1and
101-3.2)typevoltmeters.
Dynamometertypevoltmeterrangesusuallyarefrom7-U2
to750vO1ts.fullscale.DPamOmeter-typevoltmetersshouldnotbeusedoutsidetheirratedfrequencyrange.Digitaltypevoltmetersusuallyhavewiderrangesand
inmanycasesareautoranging.101.1.3 RECORDINGVOLTMETERS.
Recordingvoltmetersareusedtomeasuretransientsor
time-varyingvoltages. Figure
101.1-4showsanacceptabletypeofMethod101.lb7Downloaded from
http://www.everyspec.com.,, ,:,MIL-HDBK-705Crecording VOktmeter.
Thistypeof instrument, TexasInstruments ModelPDSHKFHXVA-A16-XT,
orGouldModel 2108-2202-005542,
shallbeusedthroughoutthegeneratrmtestsgiveninMIL-sTD-705,
unlesstherequirements of theprocurement, documentspecifically
,stateotherwise.-.101.1.4 POTENTIALTHANSFOHMERS.
Potentialtransformers(figure101.1-5)areused fortwopurposes:
toisolatethetestinginstruments
fromthelinevoltage,andtoactasmultiplyingdevicesfortheinstruments.Toobtainsatisfactoryaccuracywhenusingapotentialtransformer,itshouldbeusedunderconditionsofvoltage,frequency,
andvolt-anpereburdenthatthemanufacturerrated
itfor.Method101.lb8Downloaded from
http://www.everyspec.comMIL-HDBK-70SC9Method101.lbDownloaded from
http://www.everyspec.comMethod101.lbMIL-HDBK-705CO:ocOooc0:0)00>000)0000>0)10CiIDownloaded
from http://www.everyspec.comMIL-HDBK.70scMethod101.lbDownloaded
from http://www.everyspec.comtiIL-HDBK.70scMethod101.lb12[o a u)*
ADownloaded from http://www.everyspec.comt.iIL-HDBK-705cf..
-J13Method101.lbDownloaded from
http://www.everyspec.comMIL-HDBK-705C69Method101.lb14Downloaded
from
http://www.everyspec.comMIL-HDBK-705C/II\\II,IMethod101.lb15Downloaded
from http://www.everyspec.comMIL-HDBK-705C(DOo@FIGURE 101.1-5.
Potential transformer.IHEiIlMethod101.lbDownloaded from
http://www.everyspec.comMIL-HDBK-705CMZTHOD102.lbMSASURSFftNTOFCUFJUINT102.1.1
GENERAL. Currentisobtainedfromtheformulawhere I
isthecurrentinamperes,E isthepotentialreadinginvolts,andR
istheresistance inohms.102.1.2 INDICATINGAMMS~RS.
Whenanyammeterisused
inacircuithavingcyclicorvaryingcurrentlevels,suchaaexciterfields,itmustbe
recognizedthattheaccuracyof theinstrumentiacompromisedby
thesefluctuation, oftenby anamountthatrenders the instrument
uselessfortheintendedmeasurement.Filteringdevicesare
availableforminimizingtheeffectsof thesefluctuation.102.1.2.1
DIRECTCURRSNT. Forthemeasurementof
directcurrent,analogDAraonval-typeordigitalammeteraareused.
Self-containedinstruments ofthesetypesare availablewith full-scale
readingafrom20microampere UD to30amperea-(figure 102.l-l).Digital
ammetersareactuallydigitalvoltmetersused
inconjunctioninternalahunttodisplaythemeasuredcurrentaaaaetofnumerala.Formeasuring
currentbeyond thecapacityof theinstrumentathand,areused toextend
therangeof themeters (figure102.1-2).
Shuntsarewithanahuntaprecisionfour-terminalre;iatorsusedtomeaa&e
currentbymeasuringthevoltagedropbetweenthevoltage terminals
withthecurrentintroducedatthecurrentterminals.
Shuntsarenormallycalibratedforaspecific millivoltdropata
specificknown current. NhenDArsonvalmillivoltmetersareused
inconnectionwith
shunts,(asinanammetersystem),themillivoltratingofthemeter shouldbe
thesameas
thatoftheshuntatratedcurrentutilizingcalibratedleada.102.1.2.2
ALTERNATINGCURRENT.
Forthemeasurementofalternatingcurrents(RMS)sensingand indicating
meterssuchasdynamometers,iron-vanetypeanaloginstruments,anddigitalmeters
(figures102.1-3)normallyareused. Bycnmbiningtheseinstrumentswith
appropriate currenttranaformera, anyaccurrent measurementshaving
practicalsignificance canbemade. Becauaeof
thenonlinearcharacteristicsofmoat
analogacammeteracalea,theyshouldnotbeused inthelowerportionof
theirranges.Method102.lbDownloaded from
http://www.everyspec.com-MIL-HDBK-705c102.1.3 CURRBNTTI@NSFOSMERS.
Currenttransformers(figure102.1-4)areusedfortwopurposes;toisolate
theinstrumentfromthelinevolta~e.andtoactasamultiplyingdevicefortheinstruments.--It,iadesirabletouse
threecurrenttranaformera with
threeammeters(oroneammeterandasuitab~etransferswitch)tomeaaurethethreelinecurrentsonthree-phase,
three-wirecircuits(figure205.1-12). Iheuseof
lessthanthreecurrenttranaforrqeraisu,aua.lly notcoat-effective,
duetotimeconsumedchangingteatconnections,.andmay
notprovidethedesiredlevelofconfidenceforacceptancetea.ting.CAUTION:
ALLOWING.DIRECTCURRRNTTOFLOWINEITHERWINDING,MAYCAUSETHETRANSFORMER
CORETO BECOMEMAG~TIZED AND IMPAIRTHEACCURACYOFTHEINSTRUMENT.
INADDITION,DANGEROUSLYHIGHVOLTAGESMAY BElNDUCEDINTHESECONDARY
WINDING(PHINARY OR
SECONDARY),CAUSINGPOSSIBLEINJURYTOTSEOPEPJ.TORANDBFJ3AKDOWNOFTHEWINDINGINSULATION.
IF~GNETIZATION
ISSUSPECTEDORIFTHECALIBRATIONISNOTEVIDENT,THETRANSFORMERSHOULDBESUBMITTED
TOAPROPERCALIBRATION FACILITYFORCERTIFICATION.
INORDERTOOBTAINMAXIMUMSAFETYFOROPERATORS ANDAPPARATUS,0!?SSECONDARY
TERMINALNUSTBEGROUNDED;THEMETALCASEORCORE,IFACCESSIBLE,MUSTBEGROU~ED;
CONNECTIONSMUSTNOTBEMADEORCHANGEDWITHVOLTAGEON;THEPRIMARYOFTHETILiNSFOS$4ER
MUSTBECONNECTEDINTHELINEANDTHESECONDARYTOTHEINSTRUMENTS,
ANDNOTVICEVZRSA;ANDTRE SECONDARY OFTHETF@NSFORMER MUST Nw BEOPEWD
WITHTHECURRENTFLOWINGINTHEPRIMARY. A SHORTINGSwTCH
ACROSSTSSSECONDARYWILLBEPROVIDED.
THISSWITCHWILLBEOPENEDONLYWHENTAKINGMSTERREADINGS.
THISSWITCHNORMALLYWILLBEAPARTOFTHBCUBRENTTRANSFORMER.Method102.lb1sDownloaded
from http://www.everyspec.comM1L-HDBK-705CrFIGURE 102. l-l,
Acceptable type of self-containedde
ammeter.EiEl19Method102.lbDownloaded from
http://www.everyspec.comMIL-HDIIK-705cFIGURE02. I-2. I Dc ammeter
with rotary shunt.E3EEil20Method102.lbDownloaded from
http://www.everyspec.comMIL.HDBK-705C-m@[email protected]
from
http://www.everyspec.comMII,.HDBK-70SCMethodIl)2_lh22Downloaded
from http://www.everyspec.comMIL-HDBK-705CLMethodlo2.lb23Downloaded
from
http://www.everyspec.comMIL-RDBK-705CMETHOD103.lbMEASUREMENTOFPOWSR103.1.1
GENERAL. Mechanicalpowermostcommonlyisexpressedinhorsepower. cal
powerordinarilyisexpressedinwatts.Thereisnopracticalprimarystandardofelectricpower,thewattbeingderivedfromthevoltandampere.
However,expressed -10 Q-rboii55Method107.lbDownloaded from
http://www.everyspec.comMIL-HDBK-705C -
f=o.Method107.lb56Downloaded from
http://www.everyspec.comMIL.HDBK-705CL\oJFIGURE 107.1-2. Phase
angle meter,57 Method107.lbDownloaded from
http://www.everyspec.com.J.#-MIL-HDBK-705C;
METHOD108.lbMEASURKM31NTOFTIME108.1.1 GENERAL. Theprimarystandard
oftimeintheUnitedStatesisbasedonastr-l observations madeby
theNavalObservatoryatWashington,D.C. Timesignals
basedonthesedeterminations aresentoutbyNavalRadioStations andby
StationWWV of theNationalBureauofStandards. Secondarystandard
clocksmaybependulumcontrolledorsynchronous
clocksdrivenbyaconstantfrequency
sourcesuchasatuningfork,orcrystaloscillator.Thesesecondary
standards maybe
checkedagainsttheObservatorytimebyusingtheradiobroadcasts.108.1.2
MSCw [email protected]
useusuallyareofthestopwatchkind. Theyarespecifically designedfor
measuringtimeintervals oftheorderofanhouror less. The
startandstopmechanismsofastopwatchandclockfrequentlycauseerrorsbecauseof
lagor jumpingof thesweephandwhenthemechanismisoperated. It
isfrequentlymore
accuratetostartthewatchatapproximately10secondsbeforezeroandthenstarttheprocesstobe
timedasthehand sweepsthroughthezero.
Thepercentoferrorofastopwatchmaybeminimizedbymakingalltimeobservations
at least1minutelong.108.1.3 ELECTKIC,AL..~hERSRS .
Severaltypesofelectricaltimersareusedtomeasuretimeintervals.
Themostcommonoftheseisthesynchronousstopclock.
Thisdeviceoperatesinthesamemannerastbemechanicalstopwatcheedescribed
aboveexceptthatthehandsarestartedandstopped by a
smallmagneticclutchengagingthehandswitheithera
synchronousmotordriveorabrake.
Thus,theerrorsinvolvedinstartingandstopping aremuch lessthanthose
ofthemechanicaltim??s.
Electricaltimersofthistypedependuponthefrequencyofthepowersourcefortheirspeedandarenomoreaccuratethanthepowersourcetowhich
theyareconnected. For thisreason,theyshouldneverbedriven
bythepowerfromanengine-generator set.Digitalreadoutstopwatchesor
timersarecommonlyusedduringgeneratorsettesting.
Tnesedevicesutilizeverylowpowerdrainsolidstateelectronicsandmaybebatterypowered.Electroniccounters,utilizingcontrolledfrequencysupplies,
arequiteoften used,especiallywhere
therequiredaccuracyofthetimeintervalmeasurementishigh.108.1.4
OSCILLOGRAMTIMINGTRACES.
Oscillograms(seefigure108.1-1)alwaysrequiresomesortoftimescaleifanymeasurementsaretobemadeonthem.
Theprovisionofsuchascaleisquite simple
withmostgalvanometerstypesofoscillographs. A
standardfrequencyfromacrystalor tuningforkoscillator maybe
impressedupontheelement,oracommercialpowervoltagemaybeusedasatimingtrace.
Onanoscillogram, whenpositionistheimportantquantity
ratherthantime,as inengineindicator
diagrams,thetimingtracemaYMethod108.lb58Downloaded from
http://www.everyspec.comMIL-HDBK-705Cbesuppliedby a contactoron
theenginecrankshaft,orby amagneticpickupfroma slottedirondiskon
thecrankshaft. Oscilloscopes(figure108.1-2) maybe provided with
aso-calledZ-AXIScontrol.Thisactstoblankoutthetracewhena
signalisapplied. Thus,aperiodicpulsemaybeused
todotthetraceandconsequentlyshowtimeintervalsby
thedistancebetweendots.Oscillo-scopeswithoutZ-AXIScontrolcanbemade
to showadottedtraceby interruptingthesignalperiodically. This
lattermethod ismuchmoredifficulttocalibrateandshouldbe
avoided.whereverpossible.Method 108.lb59Downloaded from
http://www.everyspec.comMIL-HDBK-7O5CSIMULATED DATA FOR
ILLUSTRATIVE PURPOSES ONLY/TlMlN(3 WAVEFIGURE108.1-1 Sample oscil
logram, showing median 1inc.mMethod108.lb60Downloaded from
http://www.everyspec.comMIL-HDBK.70scuu1.N61Nethod108.lbDownloaded
from http://www.everyspec.comMIL-HDBK-705CMS1HOD109.lbMEASUREMENTOF
SPEED109.1.1 q. Speedofrotationisderivedbycountingrevolutions
andmeasuringelapsedtime. Thisoperationmaybe performedveryaccurately
bymeansofacounterandelectricclutch,automatically timedbya
synchronousclockandastandardfrequencysource.
Onecommerciallyavailabledeviceofthistypeiscalledachronotachometer
andisshowninfigure109.1-1.Rotationalspeed maybe
translatedtofrequency by theuseofanacgeneratordrivenby the.rotating
,element. Thisthenmaybemeasuredelectrically(see
Method104.1).109.1.2 SPEEDCOUNTERS. Oneof theways
tomeasurespeedduringa teatistocountrevo~measured timeinterval.
Thismaybe
donebyobservingthereadingaofacounterpermanentlyattachedtothemachineahaft,or
by temporarily attachingacountertotheahaft,througha friction
wheelordisk. Ineithercase,thedurationoftheobservationshouldbe
greatenoughtominimizealltheerrorsdue
tostartingandstoppingthestopwatchorcounter.In
thecaseofaportablecounter,which, inuse, isstartedandstopped,
eitherthecountershould be
startedastheclockhandsweepsthroughzero,orviceversa.
Noattemptshouldbemadetostartboththecounterandstopwatchsimultaneously.109.1.3
DIRECTBEADINGTACHOMETERS.
Severalrnethodaareusedtoindicatespeeddirectly.
Amongthemarethepositionofcentrifugalflyballs,
thevoltageofamagneto,thepressureof acentrifugal
hydraulicpump,photocellsensors,andtheeddy-currentdragofarotatingmagnetonaconducting
disk.Eachofthesedevicesmaybeusedasatachometer, andeachhas
itsownadvantagesanddisadvantages. Directreadingtachometers
areavailable
eitherforpositiveconnectiontothemachineundertest,orforhanduse.
Thelatterareshowninfigure109.1-2.Chronographs
orrecordingtachometers arespeedrecordinginstruments
inwhichagraphicrecordof
speedismade.Intheusualforqs,therecordpaperi8drivenatacertaindefinitespeedby
clockworkorweights,combined withaspeedcontrolled
motorordevicesuchthataspecificdistanceofcharttravelrepresents
adefinitetime. we penwhichmakes
therecordmaybeattachedtothearmaturesofelectromagnets,
servo-driven,oroperatedonaproportionalelectricalsignal. we
speedsensingpickupmayconsistofamechanicallycoupledtachometer
generatororamagneticproximitydevicewhosefuncti6n
istogenerateavoltage,themagnitudeof
frequencyofwhichissuppliedtotherecorder.
Somerecordersacceptelectricalsignalsdirectlyfromtheacgeneratoroutputandrecordthefrequency
onthechartasa corresponding speed(revolutions perminute).Method
109.lb62Downloaded from
http://www.everyspec.com?lIL-!rDBR-705c109.1.4 STROBOSCOPES.
Stroboscopicmethodsarec:,tciall. y
suitablefor..---,-.determiningthespeedofmachine p-rtsvbi.cllarenot
~?adiiyacceseii~le,whereitisnot practicable.to,w. er!echal!i.c~l
methods,orEotroomsusedtotestgeneratorsetsmusthaveadequatetemperaturecontroltomeet
therequirementsofthehightemperaturetest. The
averegeambientairtemperatureshallnotvarymore than3 Cthroughout
thetest,asmeasuredby thermocouplespIacedinaccordance withMethod
202.1. A
typicalhotroom,capableofmaintainingsuchtemperaturecontrolisshowninfigure114.1-1.
Thehotroomshallhaveprovision to
heattheintakeair,torecirculateacertainamountoftheheatedair,toadmitfreshair,tokeepalltheair
intheroomcirculatingandtoallowtheexcessheat
andengineexhauattoescape.
Therecirculatedairshallnotreturnwithinthehot room,butshallbe
conducted.aroundthechamberinaseparate duct.114.1.3 SIZEOF
.HOT.ROOM.Thehot roomshallbe largeenoughsothatthewalla areatleast6
feetaway fromthegeneratorset undertest, with
theexceptionthatiftheroomhas
aninnerscreenorfalaewallwiththeairpaasingonbothsidesaothatitisuniformlyat
thehotroomambienttemperature, thisscreenor!Ifalaelt wallmay be
lessthan6feet,butnot lesethan3feet,fromthegeneratoract.
Inthiscase,theouterwallmaybeasclosetothescreenor
Ifalsewallasdesired,providedthattheambientairismade
tocirculatebetweenthescreenor*ifalaewallaud theouterwall.
Itmayaleobenecessarytouseairbafflesanddeflectorsintheroomtomaintaingoodtemperature
andairflowcontrol,and,as
longaathebafflesanddeflectorsareatnearlythesametemperatureastheambientair
inthehotroom,theymaybeplacedclosertothegeneratoraetthan6feet.
Theroomshallbeat
least3feethigher,insidedimension,thanthegeneratorsetbeingtested.114.1.4
AIRCIRC Theairinthehotroomshallbe
incontinuousmotiontopreventtheformationof
localconditions,hotorcoldspots,withintheroomwhicharedifferentfrogtheaveragen
theroom.However,thechamberairvelocityshallnotexceed5mph.
Airvelocitiesgreaterthan5mph
areallowableprovidedtheincreasedvelocitiesarenecessarytomaintaintheepecifiedchambertemperature
but inno instanceshal1thevelocityexceed15mph.
Ingeneral,itiseasiertocontroltheconditionsinthehotroomiftheair
flowie fromthegeneratorendof
thesettowardtheenginecoolingairexhauat. ,114.1.5 SAPETY.
Aviewingportshouldbe installedtoallowvisualinspection of
thegeneratorsetwithoutenteringthechamber.Carbonmonoxide(CO)andexploaivemixturesdetectoreandameans
toshutdowntheaetinanemergentyarealsorequired.
Workingpereonnelshouldbe
awareofconditionswithintheteatchamberpriortoentering.Method114..
lb78Downloaded from
http://www.everyspec.comMIL-HDBK-705CLouversforCOtItrOlMultispeed .
, Of intoke ~rPLAN VIEW- -ShuttersClosed when ~alhoust Fens ore
notgyuse 1#mm2EwSECTION A-AFIGURE114.1-1. Layout
fortypicalhocroom.EEl79Method114.lbDownloaded from
http://www.everyspec.comMIL-HDBK-705CMETHOD114.2aTEMPERATLJRECONTROL(COLDROOMS)114.2.1
GENE&iL.Testchambersinwhichconditionssuchastemperature,humidity,andatmosphericpressureareaccuratelycontrolled
arecalledenvironmentalchambers. me environmental
chamberstobeconsideredinthishandbookarehotroomsj!,tcoldrooms!!,and!Ialtitudechambers,,.114.2.2
CONTKOLOFTEMt.EKATUKE.
Coldroomsusedtotestgeneratoreetsmusthaveadequatetemperaturecontroltomeet
therequirementsof thecoldtest.
Theaverageambientairtemperatureshallbeuniformwithin3Cthroughoutthetestasmeasuredby
thermocouples placedinaccordancewithMethod202.1. A
typicalcold,room,capableofmaintainingsuchtemperaturecontrolisshowninfigure114.2-1.
Thecoldroomshallhaveprovisionsto
dryandchilltheintakeair,torecirculatethechilledair,tok~epall
thesirintheroomcirculating, toremovetheheatgeneratedby theeet,and
toallowtbeengineexhausttoescape.Anestimateoftheamountofheatgeneratedbya
generatoreetoperstingatratedloadis1/3ofthetotalheatasusefulpower,1/3asexhaustheatand1/3asenginebest
toberemovedby theenginecoolingeystem.
Thisistrueforsparkorcompressionignitionenginee.
Foroperationinacoldroomtheexhaustsystem
mustbevaportight,notonlyduetothepoisonousgasesbutbecauseevena
slightleakwillemitwatervapor
totheroomwhichwillfreezetothecoolingcoils,thusloweringtheabilityof
thecoilstotransfer heat.
Inadditiontobeingvaportighttheexhaustsystemmaybe insulatedto
preventexcessive heattransfertotheroom.The
freshairintaketothechambermusthaveprovisions
todryairenteringthecoldroomaswellaschillittotheambienttemperature
of thecoldroom.A suggested
methodofdryingtheairistopassitthroughdrysilicagel. Theairdryer
musthavesufficientcapacitytosupplydryairforthedurationoftheoperational
portionof thecoldtest(s).
Dryairisdefinedasairhavingadewpointofatleast3C less
thanchamberambient.114.2.3 SI.~.OFCQ,LDROOM. Thecoldroomshallbe
largeenoughsothatthewallsareatleaat6
feetawayfromthegeneratorsetundertest,withtheexceptionthatiftheroomhas
aninnerscreenor false
wallwiththeairpassingonbothsidessothatitiauniformlyatthecoldroomambienttemperature,
thisscreenor! falsewallmaybe lesethan6
feet,butnotlessthan3feet,fromthegeneratorset.
Inthiecase,theouterwallmay
beasclosetothescreenormfal~e,tWalIasdesired,providedthattheambientairiemade
tocirculate betweenthescreenorfalse
wallandtheouterwall.Itmayalsobenecessarytouseairbafflesanddeflectorsintheroomtomaintaingondtemperature
control,and,as longas thebaff}esanddeflectOrs
areatn@arlYthesametemperature
astheambientairinthecoldroom,theymaybe
placedclosertothegeneratorsetthan6 feet.Theroomshallbeat
least3feethigher,insidedimension,thanthegeneratorsetbeingtested.Method114.2a80Downloaded
from http://www.everyspec.comMIL-HOBK-705C114.2.4
AIRCIRCULATIONINCOLDROOM. Theair inthecoldroomshallbe
incontinuousmotion toDreventtheformationof
localconditions,hotorcoldspotswithintheroomwhich
aredifferentfromtheaverageintheroom.
Itisrecognizedthatlargequantitiesofairmust
becirculatedthroughthecoolingcoilsinordertoremovetheheatgeneratedby
theequipmentundertest;how-ever,anyairmovementgeneratesheatwithin
thecoldroomandtheoptimumconditionof airflowwithin thecoldroommustbe
foundindividuallyforeachcoldroomdesign.114.2.5
ATMOSPHEREWITHINCOLDROOM.
Theambientatmospherewithinthecoldroomshall,atall
times,bechillednormalair. Atno timeshalltheroombecooledby thedirect
injectionofcarbondioxide(C02)oranyothergasorliquidotherthannormalair.
Shouldtheatmosphereof theroombecomecontaminated by any
foreigngaawhichcanaffeettheresultsof thetest,thetestshallbe
suspended,theroomclearedof theforeigngasandthetestrestarted.114.2.6
SAFETY. Aviewingportshouldbe
installedtoallowvisualinspectionofthegeneratorsetwithoutenteringthechamber.
Carbonmonoxide(CO)andexplosivemixturesdetectorsandameanstoshutdownthesetinanemergencyarealsorequired.
Workingpersonnelshouldbeawareofconditionswithintheteetchamberpriortoentering.Method114.2a81Downloaded
from http://www.everyspec.comMIL-HDBK-70scIIOTC : TUER1 SHOULDU
lIIREC WINDOWS ON CACMSIDCLEGEND@ EMOINE011iAU91 COMNIT3TIOH@
.IRCULA71N6.n *..@ lCWIN,L BOARDFORTHERMkLINSTRUMENTATIONCONDUITFOR
TltERMAL#N5TRUMEM1AT,0WIHWWINPALSCWALL7 !3%LEAPSli-V!_l-.~ ~
WINDOWTHROU31,.3.L.TION1-mfmmm, @ TERMINALBObRDFOR
GENERATORLEA.LINESAND INETWMENT LEADSY 2 d ;Ez:?FIGURE
114.2-1.}4ethod114.2a@REFR1OCRAN1 COILS@ ADJUSTABLE
WUVERSFOR,070,0, A.,- , ,9*@ ,wWNOITIOHER FOR wIIRCJJ .~
nUMID!TVANDT#.WCRATURC 0? K ..E-, .,,Schematic diagram of
controlled low temperature chamber.m82Downloaded from
http://www.everyspec.com,:
!,,MIL-HDBK-705CMETHOD114.3aTEMPERATURECONTROL(ALTITUDE
CHAMBERS)114.3.1 GENSR4L. Testchambersinwhichconditionssuchas
temperature,humidityanderic
pressureareaccuratelycontrolledarecalledenvironmentalchambers.
Theenvironmentalchamberstobe consideredinthishandbookare hotrooms,
Icoldrooms,andIaltitdechamber~t;.114.3.2 CONTROLOFTEMPERATURE.
Altitudechamberaused totestgeneratorsetsmusthave
adequatetemperature controltomeet therequirementsof
thealtitudeoperationtest.
Theaverageairtemperatureshallbeuniformwithin3Caroundtheset,and
itshallnotvarymorethan3 Cthroughoutthetest,aameasuredby
8thermocouplesplacedinaccordancewithMethod202.1.
Thealtitudechambershallhaveprovisionstoheattheintakeair,torecirculateacertainamountof
theheatedair,tokeepall theair
intheroomcirculating,toridthechamberofexcessbest,
toridthechamberofengineexhaustwhilemaintainingtheexhaustbackpressureat
thesamevalueas itwouldbe ifitwasexhaustingintothechamberproper.
o114.3.3 SIZEOFALTITUDECHAMBER. Thealtitudechambershallbe
largeenoughsothatthewalla areat least6
feetawayfromthegeneratoraetundertest,with
theexceptionthatifthechambarhaaaninnerscreenor
falsewallwiththeairpassingonboth sidesof itsothatitiauniformlyat
thechamberambienttemperature,thisscreenorfalsewallmaybe lessthan6
feet,butnot lessthan4.5 feet,fromthegeneratorset.
Inthiscaee,theouterwallofthechambarmay beasclosetothescreenor
Ifalsewallasdesired,providedthattbeambientchamberairismade
tocirculatebetweenthescreenor falsewallandtheouterwall.
Inadditiontothelnadingdoortothechambersomemethod (air-lock)shallbe
providedtoanterand
leavethechamberwithoutaffectingthechamberambienttemperature
orvacuum. Itmay
alsobenecessarytouseairbafflesanddeflectorsinthechambertomaintaingoodtemperaturecontrol,and,as
longasthebafflesanddeflectorsareatnearlythesametemperatureas
theambientair inthechamberanddonot interfere
withtheambientairthermocouples,theymaybeplacedclosertothegeneratorsetthan6feet.
Theroom shallbeat
least3feethigher,insidedimension,thanthegeneratorsetbeing
tested.114.3.4 CONTROLOFPRRSSU~ .
Ameansofcontrollingandmaintainingthepressureof thechambermustbe
provided. Tbepreaaureshallbe controlledtowithin~50 feetof
thespecifiedaltitudevalue.114.3.5 AIR CIRCULATION.
Theairinthealtitudechambershallbe incontinuousmotion
topreventtbeformationof localconditionswithinthechamberwhich
aredifferentfromtheaverageinthechamber.
Ingeneral,itiseasiertocontroltheconditionsinthechamberiftheair
flowisfromthegeneratorendof
thesettowardtheenginecoolingairexhaust.Method114.3a83Downloaded
from http://www.everyspec.com-- ;MIL-HDBK-705C114.3.6 =. Aviewing
port shouldbe installedtoallowvisualinspection
ofthegeneratorsetwithoutenteringthechamber.
Carbonmonoxide(CO)andexplosive
mixturesdetectorsandameanstoshutdownthesetinanemergencyarealaorequired.
Workingpereonnelshouldbeawareofconditionswithinthetestchamberpriortoentering.
Anemergencyrelief
valvetobringtheairpressuretotheoutsideambientpressurethatiaoperationalfrominsidethechamber,andsomemethodof
limit$ngthevacuuminsidethechambershouldbeprovided.QI+ethod114.3a84Downloaded
from http://www.everyspec.comMIL-HDBK-705cMSTHOD115.laMEASUREMENTOF
SOUNDLEVEL115.1.1 GENE~.
Forsomeapplicationsitisdesirablethatanengine-~~generatorsetoperateasquietlyaspossiblewithoutimpairingitsoperatingefficiency.
Somemanufacturingspecifications
containrequirementsforlimitsofoperatingnoise; in termsofunitaof
standardreferencesoundlevel.
Thestandardreferencelevelisdefinedas0.0002microbar
(apressureof0.0002dyneper squarecentimeter)at 1,000Hertz.115.1.2
SOUNDLEVELM?ZTSR.A soundlevelmeter
(figure115.1-1)iaaninstrumentforreading,intermsofastandardreferencesoundlevel,thesoundlevelat
itsmicrophone.
fieinstrumentconsistsessentiallyofamicrophone,electronicamplifyingand
filteringequipment,octavebandanalyzerandanindicatingmeter
calibrator.
TheAmericanNationalStandardsInstitute(ANSI)StandardsforthesemetersincludethoselistedinMIL-gTD-1474foroctave,half-octave,and
third-octave band filtersets.This
instrumentisextremelysensitivetosoundfromanysource.
Therefore,toaccuratelydeterminethenoisecharacteristics
ofageneratorset,thetestshouldbemade inaquietruralareawheresourcesof
soundotherthanfromtheunitunder testareat
aminimum.Method115.la85Downloaded from
http://www.everyspec.comMIL-HDBK-705C.7-7In,86Method11S.laDownloaded
from http://www.everyspec.comMIL-HDBK-705CMETHOD
116.lbDETERMINATIONOFPHASEROTATION116.1.1 (XWR&4L. During
anycycle,an acvoltagevariesfromzerovoltstoamaximum,tozero,
toaminimum,and finallybacktozero.Wheneachof thevoltagesofa
three-phasesystemareobservedsimultaneously,
itianotedthatthetimeofarrivalatthemaximumvoltageofeachphaseisdifferent.Ifphaseonereachesamaximum
first,followedby phasetwoandthenphasethree,thephaserotationis
1-2-3.Ifphaseonereacheamaximum,followed by
phasethreeandthenphasetwo,thephaserotationia 1-3-2.
Thisorientationoftheleadsiaimportantsincea three-phasemotorwill
runinonedirectionwhenconnected1-2-3,andinthereversedirectionifconnected1-3-2.
Moreover,iftwogener-atorsetsaretobe
operatedinparallel,thephaserotationof theconnectionsrauatbe
thesameforbothsets,ora shortcircuitwilloccur.116.1.2
PHASEROTATIONINDICATORS.116.1.2.1 MOTORTYPE. A
threephaseacmotorwithadiscorragfaatenedtotheshaftto-the
directionofrotation,whose leadsaremarkedtoshowwhichare
1,2and3,andwhosedirectionofrotationisknownwhenlead1isconnectedtophaseone,
leadtwoisconnectedtophasetwoandlead3isconnectedtophasethree,may
beused.116.1.2.2 PORTABLEINDICATORS. TWO typesofportableindicators
areavailable. The firsttypeisessentiallya
smellmotorwhosespeedofrotationislowandwhose
directionofrotationisknownandeasilyseen.
Thesecondtypeconsistsofanelectricalcircuitwith
twoneontubesappropriately inter-nallyconnectedsothatoneor
theotherwill light,dependinguponthephaserotation. Bothof
thesetypesare illustratedinfigure116.1-1.116.1.2.3
MAKESHIFTINDICATOR. Phaserotationmaybedetermined
byconnectingtwosetsof twolampbulbsinseriesbetweencorresponding
terminalsof thetestgeneratoranda sourceof
threephasevoltageofthesamefrequencyandaknownphaserotation. The
thirdterminalof
thetestgeneratorshallbeconnecteddirectlytothethirdterminalof
thesource(figure116.1-2). Ifthephaserotationof
thegeneratoristhesameas
thatofthesource,thelampswillblinksimultaneously. If
thephaserotationisnot
thesame,thelampswillblinkalternately.Method116.lbS7Downloaded from
http://www.everyspec.comMIL-HDBK-705CMethod116.lb88Downloaded from
http://www.everyspec.comMIL-HDBK.70sc( A)ll SING THREE-PHASE SOURCE
OF KNOWN PHASE ROTATION120VOLTLAMPSJ aTO 3-PHASE TO 3- PHASE
STATION POWER GENERATOROR 3-PHASE20a ~OLTS208 VOLTS!FOR
WHICHGENERATOR-PHASE ROTATIONPHASE ROTATION-T i~ IS BEINGOF WHICH
IS1208 VOLTS 208 VOLTSDETERMINEDKNOWN! ~,4 *t1t120VOLT LAMPSFIGURE
116.1-2. Makeshiftphase rotationindicator.m89Methodl16,1bDownloaded
from http://www.everyspec.com\ ..-.!-iiiL-HDBK-705CMETHOD117.
lbDETERMINATIONOFPHASERELATIONSHIP117.1.1 GENERAL.
Twoormoreacgeneratorsetsmay beoperatedinparallelprovidedthat-(
1)phasesequences,(2)voltagesand (3)frequencies arethesame.
Theusualmethodofdeterminingthattwoormoresetsareinphaseiethedimmingoftheparallelinglights.
However,somegeneratorsetscontainparallelingaiddeviceswhichmustbe
testedtodeterminetheexactphaserela-tionship
betweenthesetstitthetimethesetsareallowedtoparallel.117.1.2 ~SE
ANGLE.-. Thephaseanglemeteremployspulsemeasurementof
thedifference.intimebetweenzeroandcrossoverofthecomparedvoltages.,The
phaseanglemeterdifferentiates
theinputwavesandthedifferencesignaliadisplayedon
adirectreadingmeter inelectrical.degrees.117.1.3 OTHER.MKTHODS.
Itispossibletodeterminephase
.relationahipinvariouswaysusinginstrumegtsotherthantheaforementionedtypes.
Theseothermethods include, butarenot
limitedto,theueeofOscilloscOpes; hOwever,theset-ups,procedures and
interpretations ofresultsof theseOthermethOdsareusuallycomplex.
Beforeelectingtouseanyothermethod,carefulconsiderationshouldbegiventoitaacceptability,ease
ofcOmprehenaiOn andPOtentialfOrmisinterpretation. Ifsuchamethod
iaintendedtobeusedforgovernmentacceptanceorqualificationtests,priorapprovalofsuchuseshouldbeobtainedthroughthegovernmentcontractingofficerasearlyintheprogramaspossible.Method117.lb90IDownloaded
from http://www.everyspec.comMIL-HDBK-705C5.2
INSTRUFSSNTATIONMETHODS- 200SERIES Method117.lb91Downloaded from
http://www.everyspec.comMIL-HDBK-705CMETHOD201.lbELECTRICALINSTRUMENTS:
CARE,INSPECTION, USE,ANDREQUIRED ACCUIGiCY201.1.1 GE~RAL. The
following requirementsapplicabletoinstruments andequipmentcommonly
used inthetestingofenginegeneratorsetashallbecomplied with.201.1.2
.CA~.INSPECTIONAm USEOFINSTRUMENTS. The following
precautions..~PPIYIngeneraltO.theuse Ofelectricalinstruments
andthosemechanicallnatrumenta, employmg
Jewelbearings,smalloperatingtorques,
ordelicatemovements.Beforeanyinstrumentiaused,itshouldbe
inspectedtodeterminethatthepointerisfreeandrestsat
zero,ifapplicable. Noinstrument
shallbeusedthatsticksorbindsatanypartofthescale,orhasazeroerror.Instruments
containingpermanentmagnetashallneitherbecarriedthroughnorplacedinstrong
magnetic fieldsbecausetheaccuracyoftheinstrument
maybeaffected,Cahleacarrying high currentstoan
instrument,ornearit,shallbekeptclosetogetherandmustneverbe
placedonoppositesidesof
ironorsteelobjects,especiallyiftheyarerestingonan
ironorsteelsurface.An instrument shouldreadthesameineachof
fourhorizontalpositions, 90degreesapart,ifitiaunaffectedby
strayfielda.Instrumentashouldnotbe
dropped,bumpedagainsteachother,orplacedontablesorbenchesusedforsuchworkashammering,chipping,orriveting.
Steelpivotsrestingonjewelbearingssupportthemovingpartsofmost
instrumentsandthepressuresexertedon
thejewelbythepivotinsuchabearingisusuallYoftheorderof
severaltonspersquareinch. Forthisreason,shoc~andvi-
-brationcaneasilydamagejewelbearingsand
causeerroneousreadings.Instrument coverglasaeashouldneverbe
cleanedorrubbedwithadryclothbecauaeofthedangerofbuilding,upa
sta$icelectricchargeon theglaaa.
Ifacoverglassbecomescharged,itmaybedischargedbyrubbinggentlywithadampcloth,orbymoisteningitwith
thebreath.
Ineithercase,nomoistureshouldbeallowedtocollectinsidetheinstrumentcase.Careshouldbe
takentoavoiderrorsdue toparallaxwhenreadinganyinstrument.
Recordinginstrumentsshouldbe calibratedandreadon
thechartpapergraduation
ratherthanontheindicatorscale./Method201.lb92Downloaded from
http://www.everyspec.comMIL-HDBK-705CActual
instrumentreadingsshallbe enteredonalldatasheetsandallcurvesshallbe
carefullyplotted. Readingsshallneverbecorrectedforinstrumenterrors,
transformerratios,or scale
factorsbeforebeingenteredonthedatasheeta. When it isdesirabletohave
truevaluesappearon thedatasheet,twocolumnsshallbe used; the
firstfortheactualinstrument reading,and
thesecondforthecorrectedvalue.201.1.3 ACCURACYOF INSTR(l_~NTS .
Indicatinglaboratory-type
electricalinatrumentareferredtointhishandbook,andillustratedinsection100,shallhaveanaccuracyat
ieaat0.5percentof fullscale. Instruments willbeselectedand
connectedtoiudicatein theaccurateportionoftheirrange.Digitalmeters
generallyoffergreaterresolutionthantheanalogmodelstheyreplace.
ForMIL-STD-705testing,threesignificantdigitsarerequiredforallelectricalmeasurementsunlessadditionaldigitaareneededforclarityordefinitionfortheapplicableteat.201.1.4
PROCURElfENTDOCUMENTREQUIREMEWS . Oneof thefollowingitemsmustbe
specifiedin theindividualprocurementdocuments:a. Accuracyof
instrumentsused
foracceptancetestingshallbeinaccordancewithMIL-HDBK-705,Method201.1.b.
Accuracyof instrumentsused foracceptancetestingshallbe
inaccordancewith
(theindividualprocurementdocumentshallsyecifythedocumentor clause
Xoverning accuracyof instruments) . .Method201.lb93Downloaded from
http://www.everyspec.comMIL-HDBK-705CMETHOD202.lbTHESMALINSTRUMENTATION202.1.1.GENERAL.
Thermalinstrumentationincludesinstructionsforlocating varizsuring
devicesfordeterminingtemperatureofcomponentsandmaterials,andthesurrounding(ambient)air.Theusualmethodsofobtainingtemperatures
at thevarious locations
are:contact,resistance,ore&beddeddetector.
Eachofthesetemperature
measure-mentmethodsarediscussedindetailinMethod110,1.202.1.2
GEWE.~TOR.. SETCOMPONENTS:202.1.2.1 CONTACTMETHOD.
Thecontactmethodoftemperature measurementisusedinthe
followinglocations:
generatorbearinghousingorhousings,gen-eratorframe,statorcoils,intakeandexhaustcoolingair,collectorrings,commutator,
poletips,rotorwindings,andenginecoolantand lubeoil
(byimmersingthedetector). Temperature
measurementsonmovingcomponentamustbeattachedimmediatelyoncethemovingpartisatrest.202.1.2.2
RESIST~C3E.METHOD. @ismethodisapplicableformeasuringthetemperature
of thegeneratoroutputwinding,thegeneratorfieldandexciterfield.
Itshallnotbeused
onarotatingwindingwhosereaiatanceatambienttemperature
isleasthan1,0ohm.Theapplicationnf thedevicesand
theformulaforcalculatingthetem-peraturerisearegiveninMethod110.1.202.1.2.3
EMBEDDEDDETECTOR.METHOD. Usually,onlygeneratorsetsratedat500 kW,or
larger,areequippedwithembeddeddetectorsforthedetermination
ofthetemperature of theelectricalwindings. Ihetemperature of
stationerywindingewillbemeasuredperiodically by
thiemethodduringatest,whilethatofrotatingwindingswillbe takenata
standstill,
immediatelyfollowingshutdown.Embeddeddetectorsareoftwotypes:
thethermocouple typeandtheresistancetype. Eitherofthesetypesmaybe
employed as stationary
oxrotatingdetectors.Beforemeasuringtemperatures by
theembeddeddetector method,make
surethatthedetectorscavebeenproperiylocatedinprocurement
document.202.1.3 E.NGItfS COMPONENTS. All temperaturecomponents
normallyusethecontactmethod. Thethethermocouple
typeortheresistancetype.accordance with theapplicablemeasurementsof
theenginecontactdetectorcanbeeitherMethod202.lb94Downloaded from
http://www.everyspec.comMIL-HDBK-705C202.1.4 MBIENT
AIRTEMPERATURE.202.1.4.1 APPARATUS. Ambientairtemperature
measurementsshallbemadewithof thermometersor thermocouples.
Thesedevicesshallbe exposeddirectlytotheambientair. Nhen
chambersareused,
thethermalsensingdevicesusedforcontrollingthechambertemperatureshallbe
separatefromtheapparatususedformeasuringandrecordingthechamberambient.202.1.4.2
LOCATION.202.1.4.2.1 ENVIRONMENTALCHAMBERS. Precautions willbe
takentoinsurethatnoneof thethermometersor
thermocouplesarelocatedineitherhot*orIcoldspotsinthechamber.
Thetherm6meteraor
thermocouplesshallbeplacedatthefollowingpositions:Unhousedgeneratorset-Theambientairtemperature
shallbemeasuredatadistanceof approximately2
feetdiagonallyoutboardfromthecornersofthegeneratorsetas
theairapproachestheaet. Aminimumof2thermometers
orthermocouplesshallbe
recordedandaveragedtoestabliahtheambientairtemperaturespecifiedin
theapplicabletestdocument.
Iledistancefromwallsorobstructionsshallbe 1footminimum.
Thetemperature measurementdevicesshallnotbe locatednear
theengineexhaustoutletor
inthecoolingairexhaustfromthegeneratorset.Housedgeneratorsets-The
ambientairtemperatureshallbemeasuredatthegeneratorair
intaketothehousing. Thismeasurementshallbe takenby aminimumof
2thermometersor thermocouples.
Theoutputashallberecordedandaveragedtoestablishtheambientairtemperaturespecifiedintheappropriatetestdocument.202.1.5
CONTROLPANELTEFfPERAT.U~S . The temperature
withinthecontrolpanelenclosureshallbe takenbymeansof athermocouple.
ThethermocoupleMethod202.lb95Downloaded from
http://www.everyspec.comMIL-HDBK-705Cishallbemountedin the
spacebehindthecontrolpanelandshal1be solocatedthat
itiasurroundedonlyby airandisnot
incontactwithanyobject.Whentestingageneratorsetonwhichthecontrolpanelhasbeenopenedforin-spection,alwaysclosethecontrolpanelbeforemeasuringthetemperature
oftheenclosurebehindit.202.1.6 BATTERYELECTROLYTE
ANDBATTERYBOXAk@IENTAIRTEMTERATURJIS .202.1.6.1 BATTERYELECTROLYTE
TEMPERATURES. Thebatteryelectrolytetemperatureshal1be takenbya
thermometer
orthermocoupleintheopeningtoacentralbatterycellinallbatteriee,ifthereiamorethanone.
Nbenathermocoupleiaused, itshallbeenclosedwitha,.
corrosionresistantmaterialwhich isflexible and sealedontheend
inthebattery. Onesuchcorrosionresistantmaterialia!Teflon)t.To
inatal1thethermocouple
halfwaydowntheplates,awoodenseparatoraboutthethicknessofthethermocouple
canbecarefullyforceddownbetweentheplates,thenthethermocoupleinstalled
andtheseparatorremoved. Thethermocouple junctionshallbe
locatedsothatitiscompletelyimmersedintheelectrolyte.
Theplateswillhold thethermocoupleinplace.
Ifathermometerisused,itshallbe
locatedsothatitabulbiscompletelyimmersedintheelectrolyte..202.1.6.2
BATTERY..
BOXAMBIENTAIR,TEMPERATUKES.Thebatteryboxambientairtemperatures
shallbemeasuredbymeana oftwothermocoupleslocated
atOP?OsitesidesOfthebatterybOx,apprOximacelyhalfwayUP theinside
wall,andfreefromcontactwith anyobjectotherthantheambientair.202.1.7
~NTERIZATION HEATERTEMYERATURf$S .202.1.7.1 COOLANTTYPE HSATERS.
Forwinterizationheatersthatheatandcirculatetheenginecoolant,thetemperature
ofthecoolantshallbemeaauredatboth itsinletandoutlettotheheater.
Thetemperatureshallbetakenbythermometers or thermocoupleslocated@
thepipingatthesepoints.202.1.7.2 HOT,AIRTYPEHEATERS.
Forheatersthatheatandcirculateuncontaminated hot air,thetemperature
of
theairshallbemeasuredatitsinletandoutlettotheheater.hetemperatures
shallbemeasuredbythermocouples locatedintheheaterductsat
thesepoints.202.1.7.3 EXHAUSTGASMEASUREMENTS..~ OFHEATERS).
Theheaterexhaustgastemperatureshallbemeasuredbya thermocouple
locatedascloseaspossibletothepointatwhichtheexhaustgaaesleavetheheater.
Nhentheexhaustgasisusedinheatingtheoilpan,thetemperature of
theexhaustgas,afterpassingthroughor
aroundtheoilpan,shallalaobemeasured.Method202.lb96Downloaded from
http://www.everyspec.comMIL-HDBK-705cMSTHOD203.lbDATA
SHEETSANDKSCORDENTRIES203.1.1 $ENE~L.
Testsdonotfulfilltheirpurposeunlessaccuratedataarerecorded.Nhen
thedataarecompareddirectlywith
therequirementsofdocuments,orwhencalculationsaremade
fromtheinformationoncompleteandtheprocurementthedatasheeta,andtheresultscomparedtotherequirementsof
theprocurementdocuments,theacceptanceorrejectionof thesetunder
testisdependentuponthedataobtained.To.avoidaccepting.equipmentwhich
failstomeet therequirementsof
theprocurementdocuments,andtobeabsolutelycertain that
anyrejectsfailtomeettheserequirements,repeatanytestprocedureifthereisanydoubtas
to( theaccuracyoftherecordeddata.Eachdata sheetmust be
trackabletoacompleteseriesof information whichwill
identifythesetunder testandthe testmethod,inadditiontothedata,The
followingiswillbe included1.teat.2.3.inatruments4.TheThea
listofinformation eachdatasheetshallbe
trackabletooronthedatasheet:make,rating,modelnumber,andserialnumberof
thesetundernameandnumberofthetestmethod.Columnsforallinstrumentreadings,withtheserialnumberoftheused,andthemultiplyingfactor.Thedateonwhich
thetestnumberand thetimeof eachreading.5. Thenamesof
thepersonnelGovernmentinspector.isperformed,theconsecutivereadingperformingthetestandtheobserver/ortheunitServices6.
Noteaasnecessarytoclarifytheconditionsof thetest.7. Thenameor
designation of theagencyresponsibleforinspection ofunder teat,
Forexample: Philadelphia
Region-DefenseContractAdministration.8.dataat theof3.Data
sheetnumber.sametime,eachdataIfmore
thanonedatasheetisusedtorecordsheetusedshallbenumbered,e.g.,sheet2Method203.lb97Downloaded
from http://www.everyspec.com9. Theambient10.
ReferencesMIL-HDBK-705Ctemperature
reading.byreadingnumbertoattachedcharts.11. A seriesof instrument
readingstakenwithinfiveminutesafterstartingtheset (onlyfor tests
requiringstabilization oftheeet).NOTE: Zeroinstrument
readingawillbe recordedas such. Donotleavethespaceblank.All
instruments shallbe carefullyread.
Thereadingsshal1berecordeddirectlyon thedatasheetandnotmultipliedby
themultiplyingfactor beforerecording.
Bothmaximumandmininnqoreadingsforcyclicvaluesshallberecordedonthedatasheets.Whenmakingreadingsforsteady-state
conditions, be certainthattheseconditions
havebeenreachedbeforerecordingthereadings.Noerasuresofreadingsshallbemade.
Errorsshallbeneatlycrossedoutwithasinglestraightline. Consecutive
readingnumberswillbeginwith
thefirsttestconductedduringfiratarticle(reproduction) tests
andshallbecontinuedthroughoutthesetests.Individualtestsrequiringa
seriesofdatapointsshallberepeatedifaninterruption
occursduringthetest(e.g,,datapointsbeingtakenforplottingacurve,etc.).Complete,eccurateandneatdataareessential
whenperformingthetestsinMIL-STD-705.Samplesofdatasheetsformany
testmethodswillbe foundinMIL-STD-705.The formatofeachshallbe
followedsofaraapossible,tofacilitate
theobtainingofcomparativedata.Method203.lb98Downloaded from
http://www.everyspec.comMIL-HDBK-705CMETHOD205.lb..GENERALINSTRUCTIONSFORCONNECTINGTESTINGINSTRUFfdNTS205.1.1
GENERAL Instrumentusageisof criticalimportanceinthedetermination--
quantitativevalueofeffectsoccurringduringtests. Iftheapparatus
isimproperlyconnected,theresultingdatawilleitherbeuselessorqualitativeatbest.On
thefollowingpagesareinstructionsandschematicdiagramsindicatingthemethods
ofconnectingthemostconmonlyused instruments
requiredduringtheperformanceof themethods containedinMIL-STD-705.
Itisrecognizedthattheterminalpostsofallinstrumentsarenotin
thesameplaceas
thoseshowninthediagramsandjudgementmustbeexercisedinconnectionofanyspecificinstrument.
Themanufacturersinstructionsshouldalwaysbe consultedincaseof
doubtas totheproperutilizationofany testapparatus.The
generaltheoryofoperationof
theinstrumentsshowninthediagramaiscoveredin the100Seriesofmethodsof
thisHandbook. When recordinginstru-ments are
required,theyaretobeconnectedintothecircuitinthesamemanneras
shownforindicatinginatruments.205.1.2
CALIBIViTIONOF.,INSTRUMSNTS.All
testinstrumentsshallbecalibratedatmaximumintervalsof6months
toinsurstheiraccuracy. Testinstrumentsshallbe
calibratedwithin30dayspriortothestartofanynewteatprogram.
Instrumentsusedincalibrationshallhaveat leastfivetimestheaccuracyof
theinstrumentbeingcalibrated. Calibratedreferenceinstrumentsof
lesseraccuracythanstandard,whicharenotusedforanyotherpurpose,may
beused fortherequiredperiodiccheckof testinstruments.
Thecalibrationofall instrumentsshallbe
traceabletotheNationalBureauofStandards.Instrumentsshallbe
calibratedat thefrequenciesatwhich theyaregoingtobeused.205.1.3
>ELECTIONOF INSTRUMENTS. Priortoconnectinginstruments
intocircuits,thoughtshouldbe
giventotherangeofreadingswhichwillberequired. Therangeof
theinstrumentshouldbegreatenoughsothatitwillnotbeburnedoutduringnormaluse,but
therangeshouldnotbesogreatthatthereadingwillbe aolowon thescaleas
tomaketheaccuracyofreadingunreliable. Onanalogdc
instruments,thereadingsshallnotbemadeonthelower15percentof
thescale. Onanalogacinstruments,thereadingsshallnotbemade on
thelowerone-thirdof
thescale.Instrumentalionaccuracyshallbenotlessthan
~0.5percentofthefullscalevalue,unlessotherwisespecifiedhereinorintheprocurementdocument.Method205.lb99Downloaded
from http://www.everyspec.com., TD LDADBANKTYPEAC ammeter with
current transformers and selector switch.Downloaded from
http://www.everyspec.comMIL-HDBK.70sc70+LOAD+-o-
500Olo250FGLSHORTING SWITCHFI GURE 205. 1- 13. Self-contained
OCanmeter.m119Method205.lbDownloaded from
http://www.everyspec.comMIL-HDBK-705CCALIBRATED
LEADS/-t6aQDCAM-PIECE OF PAPER AFFIXEDTO INSTRUMENT
SHOWINGMULTIPLYING FACTOR.FI GURE 205. 1- 14. DCamneter with
shunt.mMethod 205. lb120Downloaded from
http://www.everyspec.comMIL-HDBK-705C1,I ITO LOAD.t603tET LOAD
TERMINALSo:&AC - DC1+WM@FI GURE205. 1- 15. Si ngl e phase
wattmeter.m121Method205,1bDownloaded from
http://www.everyspec.comSET LOADMIL-HDBK-705CTERMINALSLINELTO (aa
LINE aPTTO METERIIIFI GURE205. 1- 16.Method 205. l
bTOLOAD+=11PIECEOFPAPERAFFIXED/ TO INSTRUMENT SHOWINGMULTIPLYING
FACTOR.Si nqle-phase wattmeter with potential
transformer,m122Downloaded from
http://www.everyspec.comMIL-HDBK-705CSET LOAD TERMINALSi -TO LOADI0
c)f 100Q C.T~20 50010SEC~+- 0- ?1PIECE OF PAPER AFFIXEDTO
INSTRUMENT SHOWINGMULTIPLYING FACTOR.FI GURE205. 1- 17. Si ngl e-
phase wattmeter wi thcurrent transf
ormer.123lHzlMethodZoS.lbDownloaded from
http://www.everyspec.comMIL.HDBK-705C1SET LOADTERMINALS4P-rMETER*TO
LOADL3qJj*agPIECE OF PAPER AFFIXEDTO INSTRUMENT SHOWINGMULTIPLYING
FACTORFI GURE205. 1- 18. Si ngl ephase wattmeter wi th potenti al
and current transf [email protected] from
http://www.everyspec.com.....--.,-.n.r-.MIL-HU151i-/U3LI0;t-.!3zrno-Method205.lb.-.Downloaded
from http://www.everyspec.comMI L. HDBK- 70 SCblSET LOADTERMINALSTO
LOAD*Qo0100+100;C.%c) OC.T o20 50 20 500 010 10* SECQ-o-q~
SECLpoq==!7PIECE OF PAPER AFFIXEDTO INSTRUMENT SHOWINGMULTIPLYING
FACTOR.-tFIGURE 205.1-20. Sinqle-phase WBtt IiIete P on
three-phase,
three-wtrebalancedsystemUS$nqcurrenttwotransformers.mMethod205.lb,126Downloaded
from http://www.everyspec.comMIL-HDBK-705C(L23PHASE-3
WIRESETLOADTERMINALSmFTOLOAD,F]GIJRE205.1-21. Twosingle-phase
WattMeters on three-phase, three-wire system.m127 Method
Zos.lbDownloaded from
http://www.everyspec.comMIL,.HDBK-705CI>LISET LOADTERMINALSTO
LOADFI GURE205. 1- 22. Two- el ement,pol yphase wattmeter on
three-phase, three-wire system.mMethod 205.lb17RDownloaded from
http://www.everyspec.com0 -1i+16adm J3Method205.lb129Downloaded
from http://www.everyspec.comN
-1A-i!!!!MIL-HDBK-705CIIIMethod205.lb130,Downloaded from
http://www.everyspec.comMI L- HDBK-
705CSETLOADTERMINALSibkL2TOLOADrCT0020 50010SECFI GURE 205. 1-
25.uSEC~uTwo-e 1ement, polyphase wattmeter with current
transformerson balanced three-ph ase, four-wire system.m131Method
205.lbDownloaded from
http://www.everyspec.com,;MIL-HDBK-70SCAIIaOgF:+-id=IIgoii+1I,.AIEia+1aW+I000>()-e-zoem~om>+1acm+loId+ao1III0%f+l-~dIIo
l-o10+1-1z&4$Method205.lb132Downloaded from
http://www.everyspec.comMIL-HDBK-705CN
-11II1I.4I111Method205.lbDownloaded from
http://www.everyspec.com,-. .MIL.HDBK-~05CSET LOAD TERMINALSi-TO
LOADFI GURE205. 1- 28. Pol yphase wattmeter used on single-phase
system.mMethod205.lb134 Downloaded from
http://www.everyspec.comMIL-HDBK-70scSET LOADTERMINALSTO LOAD1o10*
EC-FfJM-1FIGURE 205. 1- 29. Pol yphase wattmeter with current and
potential transformers usedas a single-p base
Instrument.135Method205.lbDownloaded from
http://www.everyspec.comM1L-HDBK-705CSET LOAD
TERMINALS1br,.Method205.lb1VLWUJ+(3DFI GURE 205. 1- 30. Si ngl e-
phase power f actor meter.m136Downloaded from
http://www.everyspec.comMIL-HDBK-705CSET LOAD TERMINALSIFII*o
0+DCC. T.0020 50m- 2OmaoI1+1?1,TO METER+-11-r)FI GURE205. 1- 31. Si
ngl e- phase power f actor meter wi thpotenti al and current transf
ormers.m137 MethodZ05.lbDownloaded from
http://www.everyspec.comMIL-HDBK-705CSET LOAD TERMINALS1 -LOoIFI
GURE205. 1- 32. Three- phase power f actor
meter.mMethod205.lb138Downloaded from
http://www.everyspec.comMIL-HDBK-705C Z !!! 10-1k! N J
iitQBMethod2T5.lb139Downloaded from http://www.everyspec.comSET
LOADTERMINALS. .. . . ...MIL-HDBK-705CIw LII Iw@c)1000 C.To50
20010i sEcOQFI GURE205. 1- 34. Three- phase power f actor meter wi
th current transf ormer.Method 205. l bEmzl140Downloaded from
http://www.everyspec.comMIL-HDBK-70scI\ILISET
LOADTERMINALS:SECD(T*1000 C.T. O50 20To LoAD)LFI GURE205. 1-
35.Three- phase power f actor meter wi thpotenti al and current
transf ormers.l Xl zzzl141Method205.lbDownloaded from
http://www.everyspec.comET LOAD,., .,,.MIL-HDBK-705cTERMINALSL2FI
GURE205. 1- 36. Si ngl e- el ement wattmeter used as avarmeter on
three-phase balanced circuit.mMethod 205.lb142Downloaded from
http://www.everyspec.comMIL-HDBK.70scL2 0 -1I-.I I I I I I I I I
IbII IIPia--LJI\IIII1--------1I. Ino Nm143Method205.lbDownloaded
from
http://www.everyspec.comMIL-HDBK-705CUNEIMethod205.lb>1150FMFIGURE
205.1-38. Frequency Meter.144Downloaded from
http://www.everyspec.comMIL-HDBK-705CThF! T.TO METER~FI GURE 205.
1- 39. Frequency meter wi th potent i al transf
ormer.145Method205.lbDownloaded from http://www.everyspec.comMI L-
HDBK- 705C&----=-I(IC8RECORDINGFREQUENCYMETER/CONNECTTOOUTLET
SUPPLIEDBYPUBLICUTILITY, UT QENSET
CONVENIENCEOUTLET.FIGURE205.1-40Method205.lbRecording frequency
meter.m146Downloaded from
http://www.everyspec.comMIL-HDBK-705CII+J!!!k!&,u)+1O* L.-1NJy
x147Method2os~lbDownloaded from
http://www.everyspec.comMIL.HDBK-705CMethod205.lb148Downloaded from
http://www.everyspec.comMIL-HDBK-705C*b149Method205.lbDownloaded
from http://www.everyspec.comMIL-HDBK.70sc!!&JI
---t-lJliwlJ.~WgagMethod205.lb150Downloaded from
http://www.everyspec.comMIL.HDBK-705C9:9r
I&ia%!+mIMethod205.lb151Downloaded from
http://www.everyspec.comMIL&lBK-7oscMethod205.lb1s2Downloaded
from http://www.everyspec.comMIL-HDBK-70scPRIME MOVER!?
I=mlmiii--75T2ACAMFOR WYE - CONNECTED FORDELTA-CONNECTEDGENERATORS
GENERATORSFIELD CONNECTIONSASABOVEFORSINGLE PHASEGENERATORSTIFIGURE
205.1-47. Load instrumental ion for short circuit
currents.m153Method 205. l bDownloaded from
http://www.everyspec.comMIL-HDBK-705CMETHOD220.lbENGINEPRESSUREM?,ASUREMENTS220.1.1
GENERAL. ~e location of
thepressuretapisofimportanceintherepeatabilityzine pressure
measurements.220.1.2 AIRINT@ PRESSURS.220.1.2.1
SPARKIGNITIONENGINES. Theintake manifoldpressureshallbemeasuredby
amanometerconnectedtoapreseuretaplocatedapproximately2inchesfromthecarburetorflange.
Onsmallengineswhereapressuretapmayinterferewithcarburetion,theintake
manifoldpressuredatamay.beomittedatthedeacretionof
thetestingagency. Thepressureshallbemeasuredin inchesf at?
20ormercury (Hg).220.1.2.2 COMPRESSIONIGNITION ENGINES.
Pressureoftheintakeairinthemanifold
fornaturallyaspiratedenginesshallbemeasuredbyamanometerconnectedtoapressuretapneartheinletflangeofthemanifold.
Forengineewith scavengingairblowers,turbocharged, or supercharges,
theairpressureshallbemeasuredbyamanometerconnectedtoapreaauretaplocatedonthedischargesideof
theblower. Thepressureshallbemeasuredininchesofwater(H20)ormercury
(Hg).220.1.3 E~UST GAS PRESSURS.
Themeanexhaustgaspressureshallbemeaeured.byamanometerconnectedtoataplocatedapproximatey
2inchesbeyondtheoutletflangeof theexhaust manifoldor
turbocharger.Thepressureshallbemeasured
ininchesofmercury(Hg)o!water ( H20) . Theback pressurei mposed b, y
the l aboratory or manuf acturer s pl ant exhaust system duri ng
tests atrated net continuousloadandapeedshallnotbe
lessthanthatexistingatthesameloadandsDeedwith
thesetexhaustingdirectlytotheatmospherethroughitsownexhaustsystem,highertestpressureisandwillbe
increasedabovethisminimumspecifiedintheprocurement documents.value
ifaMethod220.lb154Downloaded from
http://www.everyspec.comMIL-HDBK-705CMethod220.2bPRESSURSANDTEM?ERATURZCORRECTIONSTO(SPARKANO
COMPRESSIONIGNITION)ENGINEDATA. .....220.2.1 ~.
Ambientairpressure,watervapor
pressureandtheintakeairtemperaturevariationshave
considerableeffecton tbeoperationalcharac-teristicsof engines. It
isnecessarytocorrectforthesevariationsinordertoassurethatengineoutputdataisuniform.220.2.2
MEASUREMENTOFATMOSPHERICMOISTURS. ~,equantityofm0i8turemixedwith
theairunderdifferentcondition8of temperatureanddegree8ofsaturation
may bemeasuredinseveraldistinctlydifferentways. M&y
ofthese,however,arenotpracticablemethodsfordaily0b8erVati0U8,.orarenotsufficientlyaccurate.
Probablythemoat convenientof allmethod8andtheonemoat
generallyemployedistoobservethetemperatureof evaporation--that
ia,thedifferencebetweenthetemperaturesindicatedbywet-bulbanddry-bulbthermometers.
Oneof themostcommonlyused
instrumentforthispurposeistheslingp8ychr0meter
(alsocalledwhirledpsychrometer).
Inspecialca8es,rotaryfansorothermeansmay beemployedtomove theair
rapidlyoverthethermometerbulbs. I nany case,
satisfactoryresultscannotbeobtainedfromobservationinrelativelyStagnantair.
A strongventilationisab801utelynecessarytoaccuracy.Additional
informationonatmosphericmoisturemeasurementcanbe
foundinANSI/ASHRAE41.6and intheASHRASbrochureonp8ychrometry.220.2.3
SLINGPSYCHROMETER.DE.SCRIPTION.Thisinstrumentc0nsi8tsofapairofthermometers,providedwithahandleas
8howninfigure220.2-1,whichpermitsthe
thermometerstobewhirledrapidly,thebulbsbeingtherebystronglyaffectedby
thetemperatureofandmoistureintheair. Thebulb of
thelowerofthetwothermometersi8coveredwith
thinmu81in,whichshaIlbewetatthetimeanobservationismade.220.2.3.1
MAINTENANCEOFTHEWETBULB. l%emuslincoveringforthewetbul b shal l be
kept cl ean and i n good condi ti on. The evaporati on of thewaterf
rom the musl i n al ways l eaves i ni ts meshes s smallquantityof
801idmaterial,whicheventuallystiffensthemuslinsothatitdoesnotreadilybecomewetafterbeingdippedinwater.
Tominimizethi8problem,usepuredi8tilled waterandrenewthemuslin
frequently. Newmuslinmust alway8bewa8hed
toremovesizing(starch)andotherpotentialcontaminant beforebeingu8ed.
A
smallrectangularpieceofmuslinwideenoughtogooneandone-thirdtimesaroundthebulb,and
longenoughtocoverthebulbandthatpartof thestembelowthemetalback,
shallbe thoroughly wettedincleanwater,andneatly
fittedaroundthethermometer. Itshallthenbe
tiedfirstaroundthebulbatthetop,usingsuitablystrongthread,thenloopedtoformaknot.arOundthebOttOmOftheMethod220.2b155Downloaded
from http://www.everyspec.comMIL-HDBK-705C.bulb,justwhereit
beginstoroundoff. As thisknotisdrawn tighter
andtighterthethreadwill
slipofftheroundedendofthebulbandneatlystretchthemuslin covering
with it,atthesametimesecuringthelatterat thebottom.220.2.4 M&NG
-~OBSERVATION USINGTHESLINGPSYCHROMETER.
Thewetbulbshallbe,thoroughlysaturated
withwaterbydippingitintoasmallcuporwide-mouthedbottle.
Thethemiometersshallthenbewhirledrapidlyfor20seconds;stoppedandquicklyread,thewetbulbfirst.
Thesereadingsshallberecorded,thepsychrometerimmediately
whirledagainanda secondsetofreadingstaken. .Thiaisrepeatedthreeor
fourtimes,ormore, ifnecessary,untilat
leasttwosuccessivereadingsofthewetbulbagree,therabyshowingthatithas
reacheditslowesttemperature.Aminuteormoreisgenerallyrequiredtosecurethecorrecttemperature.
Whentheairtemperature.ienear thefreezingpoint,thetemperature of
thewetbulbmay fallseveraldegreesbelowfreezingpoint,but thewaterwill
stillremaininthe liquidatate. No
errorresultsfromthis,providedtheminimumtemperatureisreached.
If,however,as frequently happens,thewatereuddenlyfreezes,a
largeamountofheat isliberated, andthetemperatureof thewetbulb
immediately becomes32.
Insuchcaaesitisnecessarytocontinuethewhirlinguntiltheice-covered
bulbhasreachedaminimumtemperature.220.2.4.1 NHIRLINGAm
STOPPINGTHEPSYCHROMETER. It iscliff iculttoeffectuallydescribethese
movemente. Thetechniques canonlybe learnedbypractice,
Pnearmieheldwith theforearmabouthorizontal,and thehandwellin front.
Apeculiarswingstartsthethermometers whirling,andafterward themotion
iskeptupbyonlya
slightbutveryregularactionofthewrist,inharmonywiththewhirlingthermometers.
Therateshouldbe anaturalone,soastoba easilyandregularly maintained.
Iftoofast,or irregular,thethermometersmay
bejerkedaboutinaviolentanddangerouemanner.
Thestoppingofthepsychrometer,
evenattheveryhighestrates,canbeperfectlyaccomplished
inaeinglerevolution, when onehas learnedthetechnique.Thiscanonlybe
acquiredbypractice.
Itconsistsofaquickswingoftheforearmbywhichthehandalsodescribesacircularpathandfollowsafterthethermometers
inapeculiar mannerthatwhollyovercomestheircircular
motionwithouttheslightestshockorjerk. As analternativestopping
method,thethermometers
may,withoutverygreatdanger,beallowedsimplytostopthemselves;
thefinalmotionineuchacaeewillgenerallybequitejerky,but,unlesstheinstrumentisallowedtofallonthearm,orstrikessomeobject,
noinjuryshouldreeult.220.2.4.2
SPECIALPROCEDURESFORUSINGTHEPSYCHRO~TER
IN.SUNLIGHT.Whilethepsychrometer willgivequiteaccurateindications,
eveninthebrightaunahine,observations made
inthesunshinearenotwithoutsomeerror,and,wheregreateraccuracyisdesired,thepsychrometer
shoqldbewhirledintheehedeofabui~dingortree,or,asmay sometimes
benecessary,underan ,Method220.2b.156Downloaded from
http://www.everyspec.comMIL-HDBK-705Cumbrella.
Inallcasesthereshouldbe perfectlyfreecirculationof theair,and
theobservershouldfacethewind,whirling
thepsychrometerinfrontofhisbody.
Itisagoodplan,whilewhirling,tostepbackandfortha
fewstepstofurtherpreventthepresenceof theobserversbody
fromgivingrisetoerroneousobservations,220.2.5
CORRECTINGINTAKSMANIFOLDPRESSUREOBSERVATIONS.
Themoisturevaporpressureforagivencombinationof
temperatureandrelativehumidityshallbedeterminedby
obtainingwet-bulbanddry-bulbtemperatures withaslingpsychrometer.
Thepsychrometershallbeoperatednear
theengineairintakeandthereadingsobtainedshallbeusedinconjunction
with theASHRASHandbook1981Fundamentals,chapter5and thePsychometric
Tablesof chapter6 therein,toobtainthemoisturevaporpressure.
Subtractthemoisturevaporpressurefromtheobservedvalueof
themanifoldpreseuretoobtainthedryabsolutemanifoldpressureat
theobservedtemperature.
Thedryabsolutemanifoldpressureattheobservedtemperatureshallba
convertedtoadryabaolutemanifoldpressureatthestandardcarburetorinlettemperatureof60
F(15.5C)by aPPIYingthefollowingformula:[-lD.A.M.P. atTs =D.A.M.P.
atTo 460+ 60To +460Nhere:D.A.M.P.
istheDryAbsoluteManifoldPressure.Ts
isthestandardcarburetorinletairTo
istheobservedtemperatureinF.temperature(60F).220. 2. 6
CORRECTINGMAKIMUMPOWBRVALUES. Al1valueaofobserved
maximumenginegeneratorsetoutputpowershallbe
correctedtostandardconditionsofpressureandtemperature(sealeveland60
F),unlessotherwisespecifiedintheprocurementdocument.
Correcttheobservedenginegeneratorsetoutputvaluebyapplyingthefollowingformula:Correctedwatts=
(Observed watts)29.92r460+T (Forsea leveland60F)-%%- &noNhere:
Bis the barometer i nches of mercury ( corrected f or temperature)
.Ei s thewater vapor pressure ( inchesofmercury),T
istheintakeairtemperature(F).Method220.2b157Downloaded from
http://www.everyspec.comMIL-HDBK-70SC.
,..,,,,.\Method220.2bIf158C(J$NDownloaded from
http://www.everyspec.comDownloaded from
http://www.everyspec.com;.MIL-HDBK-705CMethod222.laBATTERYSERVICING
ANDCONDITIONASSU&iNCEPRIORTO COLDSTARTING TESTS222.1.1 GENEML.
Lead-acidornickel-cadmium(NI-CAD)
batterieaareusedtostarteomee-driven electricalpowergeneratorsets.
Oneof
thepurpoaeaofMIL-HDBK-705iatoprovideguidancetoassurethatproperteatconditionsandpreparationaareaccemplishedprior.tocommencing
anyoftheMIL-STD-705tests.Nbenproviaionsaremade
inadvancetoaasurethatadequatefacilitiea,equipmentandpersonnel
willbeavailable,
batteryservicingandconditionassurancecanusuallybeaccomplished
withinanormal5-daywork-week.
PlanningandschedulingforMIL-sTD-705testingshouldallowsufficient
pre-testtimeforthesetaaka.The
testsofMIL-STD-705,whenusedforfirstarticleorproduction
acceptance,aretoverifythatgeneratorsetshavebeenproperlymanufactured,
nottoteatbatteries.
Batteriesaremulti-useitemstestedandqualifiedundertheirownseparate
programs,priortobeingspecifiedforuaeongeneratorsetsorvariousotherequipment.
BatteriesthatareusedduringMIL-ST.D-705firstarticleorproduction
acceptancetestingare,inessence,testsupportequipment.
Iffullbatteryoutputcapabilityisnotaasuredpriortogeneratorsettesting,inadequate
batteryperformance maycauaeabortionofanotherwise
validteatsequence;thiscanresultinwaatsoftestfacilityandpersonnelresources,andriskfailuretomeetcontractorprogramschedules.
Operational experiencewiththeprocedures
belowiathattheyarehighlyeffectiveinpreventingsuchproblems.NhenthetestsofMIL-STD-705areused
forevaluation duringequipmentrasearcbanddevelopment,
theuseornon-useoftheproceduresbelowdependsuponthepurposeforwhichthetestdatawillbeused.
Forexample,totalsystemreliability
oroperationalreadineasasaesaments, evaluations
ofcomponentcompatibilities, standardization
studiesandaoforth,wouldprobablynotrequiretheuseof
thesebatteryconditioning procedures.222.1.2 PRRPAFuiTI.ON
OFBATTERIES
y~.Itis8tronglyrecommendedthatnewbatterieabeusedforthecoldstartingtestsofMIL-STD-705,tofurther
minimizepossibilitiesoftestabortionsduetoimproper
batteryconditions. Extremecaremustbe
exercisedtoinsurethatNI-CADbatteriesarenotcontaminated by
tools,equipment,solutions orgasesfromlead-acidbatteries.
Suchcontamination candestroyNI-CADbatteries. RefertotheNI-CAD
battery techni cal manual or manuf acturer a data f or f urther gui
danceabout thi s.Batteries
maybereceivedineitherthewetordrycOndition.
Wetbatterycellsalreadycontaintheelectrolytesolution,
whereasdrybatteriesrequirefilling
withelectrolytesolutionafterreceipt. Somebatteries
mayhaveMethod222.la160Downloaded from
http://www.everyspec.comMIL-HOBK-705Csealingdevicesovereachcel1forshipmentandstorage,whichmustbedislodged(andcanbediscardedor
leftinsidethecells)priortofilling.
Wetbatteriesmayrequiretoppingoffwith dietilledwater
tobringtheelectrolytetoitscorrectlevel,but neither
toppingoffofwetbatteriesnor fillingofdrybatteriesshouldbe
attempteduntil thebatteryhasstabilizedata temperaturebetween60 F
(15.6C)and 100 F (37.8C). Stabilization
shouldbeverifiedby3consecutivechecksof
thebatteryorelectrolytetemperature,10minuteeapartandvaryingwithin~5
F(2.8C)of eachother,withinthe60 Fto100Frange.
Finalcheckandadjustmentof
theelectrolytelevelshouldthenbemade30minuteeafteranypreviousadditionsofdistilledwaterorelectrolyte.Theelectrolytefordrylead-acidbatteriesis